User manual | MG U MVP Relay Light System

June 15, 2003

Lit. No. 21857

SNOWPLOWS

®

MECHANIC'S GUIDE

CAUTION

Read this manual before servicing the WESTERN

MVP

snowplow.

TABLE OF CONTENTS PREFACE

Preface ............................................................................................................. 2

Safety Information ........................................................................................... 3

Tools Required ................................................................................................ 5

Product Specifications .................................................................................... 5

Hose Routing ................................................................................................... 6

MVP

FloStat ® Parts Diagram ......................................................................... 7

Solenoid Cartridge Valve Identification and Location .................................. 8

Relief Valve Identification and Location ........................................................ 9

Pilot Operated Check Valve Identification and Location ............................ 10

Vehicle Harness and Vehicle Cable Location .............................................. 11

Operating the Snowplow .............................................................................. 12

Theory of Operation ...................................................................................... 15

Hydraulic and Electrical Schematics ........................................................... 17

Electrical Schematic ......................................................................... 18

Hydraulic Schematic ........................................................................ 19

Angle Right ....................................................................................... 20

Angle Left .......................................................................................... 22

Right Retract ..................................................................................... 24

Right Extend ..................................................................................... 26

Left Retract ........................................................................................ 28

Left Extend ........................................................................................ 30

Scoop ................................................................................................ 32

Vee ..................................................................................................... 34

Raise .................................................................................................. 36

Lower ................................................................................................. 38

Hold in Raise Position – Hydraulic .................................................. 40

Striking an Object While Plowing Forward – Hydraulic ................. 41

Striking An Object While Back Dragging – Hydraulic .................... 42

Headlamps – Vehicle Only ............................................................... 43

High Beam Headlamps With Plow Connected to Vehicle .............. 44

Low Beam Headlamps With Plow Connected to Vehicle ............... 45

Troubleshooting Guide ................................................................................. 46

Removable Spring Tool ................................................................................. 70

Terminal Removal Tool and Terminal Replacement ................................... 71

This guide has been prepared to assist the trained mechanic in the service of WESTERN ® snowplows. It also provides safety information and recommendations. We urge all mechanics to read this manual carefully before attempting to service the WESTERN snowplow equipment covered by this guide.

Service of your WESTERN snowplow equipment is best performed by your local Western Products outlet. They know your snowplow best and are interested in your complete satisfaction.

Lit. No. 21857 June 15, 2003

SAFETY INFORMATION

WARNING

Indicates a potentially hazardous situation that, if not avoided, could result in death or serious personal injury .

CAUTION

Indicates a situation that, if not avoided, could result in minor personal injury and/or damage to product or property.

NOTE: Identifies tips, helpful hints and maintenance information the owner/operator should know.

BEFORE YOU BEGIN

WARNING

Lower blade when vehicle is parked. Temperature changes could change hydraulic pressure, causing the blade to drop unexpectedly or damaging hydraulic components. Failure to do this can result in serious personal injury.

WARNING

Remove blade assembly before placing vehicle on hoist. Failure to do this could result in personal injury.

Lit. No. 21857

WARNING

Do not exceed GVWR or GAWR

(including blade and ballast) as found on the driver-side door cornerpost of the vehicle.

• Park the vehicle on a level surface, place shift lever in

PARK or NEUTRAL and set parking brake.

•

Leave the snowplow mounted on the vehicle and lowered for most service procedures, unless told otherwise.

PERSONAL SAFETY

• Wear only snug-fitting clothing while working on your vehicle or snowplow.

• Do not wear jewelry or a necktie, and secure long hair.

• Be especially careful near moving parts such as fan blades, pulleys and belts.

• Wear safety goggles to protect your eyes from battery acid, gasoline, dirt and dust.

• Avoid touching hot surfaces such as the engine, radiator, hoses and exhaust pipes.

• Always have a fire extinguisher handy, rated BC for flammable liquids and electrical fires.

VENTILATION

WARNING

Vehicle exhaust contains deadly carbon monoxide (CO) gas.

Breathing this gas, even in low concentrations, could cause death. Never operate a vehicle in an enclosed area without venting exhaust to the outside.

If you work on the vehicle or snowplow in a garage or other enclosed area, be sure to vent exhaust gas directly to the outside through a leakproof exhaust hose.

FIRE AND EXPLOSION

WARNING

Gasoline is highly flammable and gasoline vapor is explosive.

Never smoke while working on vehicle. Keep all open flames away from gasoline tank and lines. Wipe up any spilled gasoline immediately.

Be careful when using gasoline. Do not use gasoline to clean parts. Store only in approved containers away from sources of heat or flame.

HYDRAULIC SAFETY

WARNING

Hydraulic oil under pressure could cause skin injection injury. If you are injured by hydraulic oil, get medical treatment immediately.

• Always inspect hydraulic components and hoses before using. Replace any damaged or worn parts immediately.

• If you suspect a hose leak, DO

NOT use your hand to locate it.

Use a piece of cardboard or wood.

June 15, 2003

SAFETY INFORMATION

BATTERY SAFETY

CAUTION

Batteries normally produce explosive gases which can cause personal injury.

Therefore, do not allow flames, sparks or lit tobacco to come near the battery. When charging or working near a battery, always cover your face and protect your eyes, and also provide ventilation.

Batteries contain sulfuric acid which burns skin, eyes and clothing.

Disconnect the battery before removing or replacing any electrical components.

Please become familiar with and make owners knowledgeable of the Warning and Instruction labels on the back of the blade!

Instruction Label

Warning Label

WARNING

LOWER BLADE WHEN VEHICLE IS PARKED.

REMOVE BLADE ASSEMBLY BEFORE PLACING VEHICLE

ON HOIST.

DO NOT EXCEED GVWR OR GAWR INCLUDING BLADE

AND BALLAST.

CAUTION

READ

OWNER'S MANUAL

BEFORE OPERATING OR

SERVICING SNOWPLOW.

TRANSPORT SPEED SHOULD NOT EXCEED 45 MPH.

REDUCE SPEED UNDER ADVERSE TRAVEL

CONDITIONS.

PLOWING SPEED SHOULD NOT EXCEED 10 MPH.

SEE YOUR WESTERN OUTLET FOR APPLICATION

RECOMMENDATIONS.

59900

Instruction Label

Lit. No. 21857 June 15, 2003

REQUIRED TOOLS

PRODUCT SPECIFICATIONS

For servicing the electrical and hydraulic system

Required:

• Long/Slender Needle Nose

Pliers

• Flat Screwdriver

• Combination Wrenches: 3/8",

7/16" (2), 1/2", 11/16", 3/4", 7/8"

• 1/4" Socket or Nut driver

• 12V Test Light

• Torque Wrench (IN-LB)

Recommended :

• Combination Wrenches:

1-1/16", 1-1/8"

• Deep Sockets: 11/16", 7/8",

1-1/16", 1-1/8"

• Volt/Ohm Meter

• Pencil Magnet

• 3000 PSI Pressure Gauge

For replacing trip springs :

• Removable Spring Tool — available from your Western

Products outlet

V-Plow Specifications

Hydraulic System

Relief valve settings

• Pump relief valve = 1750 PSI.

2 1/2 - 2 3/4 turns CCW from fully seated

• Primary relief valve = 3000 PSI.

1 1/2 - 1 3/4 turns CCW from fully seated

• Secondary relief valve = 3500

PSI. 1 1/4 - 1 1/2 turns CCW from\ fully seated

Fluid Capacity—Hydraulic Oil

• Unit Reservoir = 1 3/4 Quarts

• System Total = 2 1/2 Quarts

Hydraulic Oil

CAUTION

Do not mix different types of hydraulic fluid. Some fluids are not compatible and may cause performance problems and product damage.

• WESTERN ® High Performance

Fluid to -25°F (-32°C)

• Automatic Transmission Fluid

(ATF) Dexron III to -10°F

(-23° C) or,

• Texaco 1537 Aircraft Hydraulic

Oil for temperatures below

-25° F (-32°C).

Solenoid Valve Spool Travel = 0.07

Inches for three way and four way valves

Electrical System – approximate values:

• Solenoid Coil Resistance =

7 Ohms at room temperature

• Solenoid Coil Amp. Draw =

1.5 Amp.

• Motor Relay Coil Resistance =

16 - 17 Ohms

• Motor Relay Amp. Draw =

0.7 Amp.

• Maximum Motor Amp. Draw =

190 Amp. at 1750 psi.

• Headlamp Relay Coil

Resistance = 106 Ohms

• Headlamp Relay Amp Draw =

0.1 Amp.

Fuse Size

• Harness – 10 Amp.

(10AFB 3AG)

• Circuit Board (2) – 5 Amp.

(5AFB SMD)

Lit. No. 21857

Mechanical

Fastener Torque for :

• Pump Bolts = 150–160 IN-LB

• Motor Bolts = 30–40 IN-LB

• Reservoir Bolts = 15–20 IN-LB

• Cartridge Torque = 120 IN-LB

• Check Valve Torque =

120 IN-LB

• Coil Nut Torque = 48–60 IN-LB

• Secondary Manifold Block

Assembly Bolt Torque =

108 IN-LB

• Angle Cylinder

Piston Locknut Torque =

100-120 FT-LB

Gland Nut Torque =

150-180 FT-LB.

June 15, 2003

HOSE ROUTING

Hydraulic Unit

90°Street Elbow and Straight Swivel

18" Hose

38" Hose

Lit. No. 21857

45° Swivel

38" Hose

Base End

Lift Cylinder

36" Hose

Driver Side (Left)

Angle Cylinder

Base End

Passenger Side (Right)

Angle Cylinder

Base End

36" Hose

June 15, 2003

MVP

FLOSTAT

PARTS DIAGRAM

Old Style

Oil Pick Up Tube

Reservoir

Pump Filter

Pump

Oil Return Line

Solenoid Valve Coil

Solenoid Valve Cartridge

Primary Valve

Block

Quill

Motor

Relief Valve

Pilot Operated

Check Valve

Secondary Valve

Block

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SOLENOID CARTRIDGE VALVE IDENTIFICATION AND LOCATION

Solenoid Cartridge ValveS1

(SV08-2004)

Solenoid Cartridge ValveS3

(SV08-43)

Solenoid Cartridge ValveS2

(SV08-40)

Solenoid Cartridge

ValveS5

(SV08-40)

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Solenoid Cartridge ValveS6

(SV08-30)

Solenoid Cartridge ValveS4

(SV08-30)

June 15, 2003

RELIEF VALVE IDENTIFICATION AND LOCATION

Lit. No. 21857

Pump Relief

Valve

Left Secondary

Relief Valve

Left Primary

Relief Valve

Right Secondary

Relief Valve

Right Primary

Relief Valve

June 15, 2003

PILOT OPERATED CHECK VALVE IDENTIFICATION AND LOCATION

Pilot Operated (P/O)

Check Valve B

Lit. No. 21857

Pilot Operated (P/O)

Check Valve D

Pilot Operated (P/O)

Check Valve C

Pilot Operated (P/O)

Check Valve A

June 15, 2003

VEHICLE HARNESS AND VEHICLE CABLE LOCATION

To Negative

Battery Terminal

22" Red Cable

Black Wire

-

+

Motor Relay

Secondary

(Large)

Terminals

Faston

Connector

Vehicle Cable

Assembly

Orange/

Black

Red Wire

Vehicle

Harness

Control

LOW

MODE

RAISE

FLT

PWR

ON/OFF

Switch

Control

Bracket

Primary

(Small)

Terminals

Brown/Red

Brown/Green

Firewall

Grommet

14-pin Connector

(in-cab)

Red Wire

Fuse

Holder

Vehicle Cable

Assembly

Connector

Vehicle

Harness

Connector

Self-Stripping

Connector (Blue)

Wires to

Headlamp Relays

Vehicle Wire Controlled by Ignition Switch

Lit. No. 21857 June 15, 2003

OPERATING THE SNOWPLOW

CabCommand Hand-Held Control

WARNING

The driver shall keep bystanders clear of the blade when it is being raised, lowered or angled. Do not stand between the vehicle and the blade, or within 8 feet of a moving blade. A moving or falling blade could cause personal injury.

CAUTION

To prevent accidental movement of the blade, always turn the ON/OFF switch to OFF whenever the snowplow is not in use. The control indicator light will turn off.

Turn the vehicle ignition switch to the ON or the ACCESSORY position.

Press the PWR button on the control. The control indicator light will glow red indicating the control is on. The control indicator light will glow red whenever the control ON/OFF switch and the vehicle ignition switch are both ON and the plow plugs are connected to the grill connectors.

Function Time Outs

All control functions, except for

LOWER, automatically time out— stop—after a period of time. This is to help prolong the battery charge. The time-out period for the RAISE function is 2.5 seconds, while all others are 4.25 seconds.

The control will automatically turn off after being idle for 20 minutes.

SMOOTH STOP

The control automatically allows the blade to coast to a stop. This results in smoother operation, reduces the shock to the hydraulic system and increases hose and valve life.

Lit. No. 21857 June 15, 2003

OPERATING THE SNOWPLOW

Straight Blade Mode—Default

The control automatically defaults to the straight blade mode when turned on. The MODE lamp, near the MODE key in the upper left corner of the keypad, will not be illuminated or flashing when the control is in the straight blade mode.

The functions shown at right are performed in the straight blade mode:

Button Description of Operation

Raise

Lower

L / SCP

R / VEE

Press this button to raise the plow and to cancel the float mode.

NOTE: Plow will automatically stop raising after 2.5 seconds. To resume raising the plow, release the button and press again.

Press this button to lower the plow. NOTE: After reaching the desired height, release the button. Holding the button down for more than 3/4 second will activate the float mode, indicated by green FLT lamp.

Press this button to angle both wings to the left.

Press this button to angle both wings to the right.

Vee/Scoop Mode

Quickly press and release the MODE key to put the control into the vee/ scoop mode. The MODE lamp, near the upper left corner of the keypad, will light. Quickly pressing and releasing the MODE key will toggle the control between straight blade mode and vee/scoop mode.

The functions shown at right are performed in the vee/scoop mode:

Button Description of Operation

Raise

Lower

L / SCP

R / VEE

Press this button to raise the plow and to cancel the float mode.

NOTE: Plow will automatically stop raising after 2.5 seconds. To resume raising the plow, release the button and press again.

Press this button to extend both wings to the scoop position.

Press this button to retract both wings to the vee position.

Lit. No. 21857 June 15, 2003

OPERATING THE SNOWPLOW

Wing Mode

To put the control into the wing mode, press and hold the MODE key for about two seconds until the MODE lamp near the upper left corner of the keypad is flashing. The L / SCP and

R / VEE keys are used to activate the four functions of the wing mode. The

RAISE and LOWER keys function the same as in the other modes.

The functions shown at right are performed in the wing mode:

Button

Raise

Lower

L / SCP

R / VEE

Description of Operation

Press this button to raise the plow and to cancel the float mode.

NOTE: Plow will automatically stop raising after 2.5 seconds. To resume raising the plow, release the button and press again.

Press this button to lower the plow. NOTE: After reaching the desired height, release the button.

Holding the button down for more than 3/4 second will activate the float mode, indicated by green FLT lamp.

Pressing this button the first time will retract the left wing.

Pressing this button the next time will extend the left wing.

Pressing this button the first time will retract the right wing.

Pressing this button the next time will extend the right wing.

Lit. No. 21857 June 15, 2003

THEORY OF OPERATION

Plow Hydraulics

The MVP ® snowplow

FloStat ® hydraulic system

CONTROLLER MODE

STRAIGHT BLADE

(DEFAULT)

WING performs 10 blade movement functions.

All functions require the vehicle ignition (key) switch to be in the run or accessory position and the power to be activated on the snowplow cab control.

CONTROLLER BUTTON

BLADE

MOVEMENT

R/VEE

ANGLE

RIGHT

L/SCP

ANGLE

LEFT

R/VEE *

RIGHT

RETRACT

R/VEE *

RIGHT

EXTEND

Low side drive provides a common live hot (12V) to all of the loads (coils, relay, etc.). When the cab control is activated, the ground path is closed

L/SCP *

LEFT

RETRACT

L/SCP *

LEFT

EXTEND

V / SCOOP

L/SCP

SCOOP

R/VEE

VEE

ALL

RAISE

ALL

LOWER

LOWER large current flow which energizes the motor, which in-turn rotates the internal pump and creates fluid flow.

(Motor relay does not energize in

“lower” function).

Nine of the ten hydraulic functions require energizing the electric motor, shifting of solenoid cartridge spools or activating p/o check valves. The tenth function, lower, does not energize the motor but requires shifting of solenoid cartridge spools.

Operation of Electrical Circuit:

The electrical drive circuit that is used for the MVP snowplow hydraulics is defined as a low side drive system.

to complete the circuit, energizing the selected coils and/or relay. The current flow through the coils produces a magnetic field which shifts the spools in the cartridges.

The cartridges direct the fluid flow to the appropriate passages to produce the selected blade movement function. Current flow also energizes the motor relay, closing the motor relay contacts connecting the motor to the battery through heavy electrical cables. The heavy cables carry a

Testing Low Side Drive Systems:

To test a low side drive system, connect the negative lead of the test instrument (volt meter) to ground and the positive lead to the negative side of the load (coil, relay, etc.). A reading of 12 volts should be indicated when the load is not activated. A reading of near 0 volts when load is activated.

Lit. No. 21857 June 15, 2003

THEORY OF OPERATION

Plow Headlamps

The headlamp circuit operates using a high side drive system. High side drive provides a hot 12V source to activate the loads (coils, relays, etc.) that share a common ground. The headlamp switching circuit uses two single pole double throw (SPDT) relays. When combined with the snowplow plug-in headlamp harness and the vehicle harness, the relays will automatically switch between plow and vehicle headlamps as the plow plugs are connected and disconnected.

The vehicle harness has a brown wire that is spliced into the vehicle park lamp circuit. This wire feeds the plow park lamps through the grill connector and also powers the coils of both relays. The other terminal of the relay coils is connected to the black/orange ground wire which also goes to the grill connector. When both the plow and battery cable plugs are connected to the grill connectors, a ground is completed for the relay coil. When the vehicle park lamps are turned on and the plugs are connected, the relay coils will be activated. This causes the relay contacts to switch from the normally closed contacts to the normally open contacts. The normally closed contacts power the vehicle headlamps. The normally open contacts power the plow headlamps.

Refer to the Headlamp Test Diagram in the Troubleshooting Guide.

It should be noted that:

• The relay with the yellow, orange and black wires operates the low beam headlamps.

• The relay with the green, red and white wires operates the high beam headlamps.

• The parking lamp circuit provides power to both relays at the same time.

• Both plow plugs (12 pin and battery cable) need to be connected and the headlamp switch must be on for the relays to activate.

Daytime Running Lights

An additional fused pink wire is used in place of the brown park circuit wire to introduce power to the light relays.

The pink wire is connected to a circuit controlled by the vehicle ignition switch. When the vehicle ignition is on and the grill connector plugs are connected the relay coils will be activated. This allows the DRLs to be switched to the plow lights when the vehicle headlamp switch is off. DRLs use the same circuit as the regular headlamps.

Testing High Side Drive Systems:

Connect the negative lead of the test instrument (voltmeter) to ground and positive lead to the positive side of the load. A reading of 12 volts should be indicated when the load is activated; zero volts when load is not activated.

Lit. No. 21857 June 15, 2003

HYDRAULIC AND ELECTRICAL SCHEMATICS

The following section contains hydraulic and electrical schematics to help explain how the hydraulic unit performs the different functions. A schematic is an abstract drawing showing the purpose of each of the components in the system. Each component is represented by a graphical symbol. The hydraulic and electrical legends list and describe each of the symbols used in the schematics for this guide.

The first two schematics show a general overview of the complete hydraulic and electrical systems. The remainder of the schematics have been altered to highlight flow of hydraulic oil and electrical current for each function the hydraulic unit performs or flow of electrical current for the snowplow and vehicle lights.

• Bold lines represent the circuit being activated only.

• Shaded components are either activated or shifted from their normal position.

NOTE:

Left side = Driver side

Right side = Passenger side

HYDRAULIC LEGEND

LINE, WORKING (MAIN)

LINE, PILOT (FOR CONTROL)

LINES JOINING

LINES CROSSING

FLOW, DIRECTION OF

HYDRAULIC FLUID

LINE, TO RESERVOIR

BELOW FLUID LEVEL

HYDRAULIC PUMP

FIXED DISPLACEMENT

CYLINDER

ELECTRIC MOTOR

FILTER,STRAINER

DIFFUSER

COMPONENT ENCLOSURE

SPRING

SOLENOID, SINGLE WINDING

PILOT OPERATED (P/O)

CHECK VALVE

VALVE, ADJUSTABLE

PRESSURE RELIEF

VALVE, FLOW CONTROL,

ADJUSTABLE-

NON-COMPENSATED

VALVE, TWO POSITION

TWO CONNECTION

(TWO WAY)

VALVE, TWO POSITION

THREE CONNECTION

(THREE-WAY)

VALVE, TWO POSITION

FOUR CONNECTION

(FOUR-WAY)

ELECTRICAL LEGEND

CROSSING WIRE

WIRE SPLICE

IN LINE CONNECTOR

WIRE CONTINUES

ELSEWHERE

FUSE

SOLENOID

CIRCUIT GROUND

MOTOR RELAY

M +

BATTERY

MOTOR

LIGHT

COMPONENT ENCLOSURE

Wire Color Code

BLK Black BRN/RED Brown w/ Red LTBLU/ORN Light Blue w/ Orange TAN Tan

BLK/ORN Black w/ Orange DKBLU

BLK/RED Black w/ Red DKBLU/ORN

Dark Blue LTBLU/WHT Light Blue w/ White

Dark Blue w/ Orange LTTAN Light Tan

VIO

WHT

BLK/WHT Black w/ White DKBLU/WHT Dark Blue w/ White ORN Orange

Violet

White

WHT/YEL White w/ Yellow

YEL Yellow BLU Blue GRN

BLU/ORN Blue w/ Orange GRY

BRN Brown LTBLU

Green

Gray

Light Blue

ORN/BLK

PNK

PUR

Orange w/ Black

Pink

Purple

BRN/GRN Brown w/ Green LTGRN Light Green RED Red

Abbreviations

DRL Daytime Running Lights

MTR RLY Motor Relay

P/T SIG Park / Turn Signal

Lit. No. 21857 June 15, 2003

ELECTRICAL SCHEMATIC

PLOW ASSEMBLY

RIGHT SIDE PLOW LAMP

P/T SIG

HEADLAMP

PUR

BRN

PUR

BRN

PUR

BRN

WHT

BLK/ORN

BLK

BLK/ORN

(GROUND)

WHT (HIGH BEAM)

BLK (LOW BEAM)

S1 SOLENOID

WHT/YEL

S2 SOLENOID

LT BLU

S3 SOLENOID

LT GRN

S4 SOLENOID

BLK/WHT

S5 SOLENOID

BLU/ORN

S6 SOLENOID

LT BLU/ORN

RED

BLK/ORN

PUMP MOTOR

#6 RED

#6 BLK

HEADLAMP

BRN

RED

P/T SIG

BRN

T RED

LEFT SIDE PLOW LAMP

BLK

BLK/ORN

WHT

BRN

GRY

Lit. No. 21857

COMPONENTS LOCATED NEAR FRONT OF VEHICLE

BLU (GND)

TO VEHICLE

HEADLAMPS

RED (HIGH)

ORN (LOW)

TO RIGHT TURN

LAMP BULLET

TO LEFT TURN

LAMP BULLET

TO PARK

LAMP BULLET

PUR

GRY

BRN

WHT

HIGH

BEAM

87A

86 85

BRN

RED RED

WHT/YEL

BLK

LT GRN

LT BLU

BLK/ORN

WHT

BLK/WHT

BLU/ORN

GRY

PUR

BRN

LT BLU/ORN

#6 BLK

RED

#6 RED

WHT/YEL

BLK

LT GRN

LT BLU

BLK/ORN

WHT

BLK/WHT

BLU/ORN

GRY

PUR

BRN

LT BLU/ORN

#6 BLK

RED

#6 RED

RED RED

BLU (GND)

GRN (HIGH)

YEL (LOW)

FROM VEHICLE

HEADLAMP

CONNECTOR

LOW

BEAM

BLK

87A

86 85

BLK/ORN

87A

10AFB

RED

IGNITION

LT BLU/ORN

BLU/ORN

BLK/WHT

LT GRN

LT BLU

WHT/YEL

BRN/RED

RED

ORN/BLK

BRN/GRN

LOCATED UNDER DASH COIL CORD HARNESS

ORN/BLK

LOCATED NEAR BATTERY

#6 RED

MTR RLY

#6 RED

BRN/GRN

BLU

GRN

RED

TAN

BRN

BLK

YEL

VIO

GRY

WHT

ORN

#6 BLK

BRN/RED

** HAND HELD

CONTROL

REPRESENTATION

OF PRINTED

CIRCUIT BOARD

June 15, 2003

HYDRAULIC SCHEMATIC

RIGHT

LEFT

PRIMARY

RELIEF

VALVE

SECONDARY BLOCK ASSY.

3000 PSI

PRIMARY

RELIEF

VALVE

SECONDARY

RELIEF VALVE

3500 PSI

P/O

CHECK

VALVE

(C)

(D)

P/O

CHECK

VALVE

SECONDARY

RELIEF VALVE

3500 PSI

3000 PSI

PRIMARY BLOCK ASSY.

CONTROLLER MODE

CONTROLLER BUTTON

BLADE

MOVEMENT

MOTOR

SV08-2004

SV08-40

SV08-43

SV08-30

SV08-40

SV08-30

STRAIGHT BLADE

(DEFAULT)

R/VEE L/SCP

ANGLE

RIGHT

ANGLE

LEFT

WING

R/VEE * R/VEE * L/SCP * L/SCP *

RIGHT

RETRACT

RIGHT

EXTEND

LEFT

RETRACT

LEFT

EXTEND

V / SCOOP

L/SCP R/VEE

SCOOP VEE

ON ON

ALL

RAISE

ALL

LOWER

RAISE

LOWER

ON ON

LIFT

* NOTE - SEE BLADE MOVEMENT TEXT

FOR BUTTON OPERATION

Lit. No. 21857

P/O CHECK

VALVE

(A)

P/O

CHECK

(B)

1750 PSI

PUMP

RELIEF

VALVE

June 15, 2003

ANGLE RIGHT – ELECTRICAL

Blade Movement: Angle Right

Controller Mode: Straight Blade Mode

(Default)

Controller Button: R/VEE

System Response:

1) By pressing the controller button, the circuit board within the cab control completes the ground path for the electrical circuit.

PLOW ASSEMBLY

RIGHT SIDE PLOW LAMP

2) Electrical current flows through the motor relay, activating the pump motor, and solenoid cartridge valve S5, shifting its spool.

3) Hydraulic oil from the pump flows through solenoid cartridge valve

S2, P/O check valve (B) and into

5) the rod end of the right cylinder causing it to retract.

4) Pressure within the hydraulic circuit causes P/O check valves

(A) & (D) to open.

The retracting right cylinder pushes the hydraulic oil out of its base end, through solenoid

COMPONENTS LOCATED FRONT LEFT OF VEHICLE

BRN

S1 SOLENOID

S2 SOLENOID

S3 SOLENOID

S4 SOLENOID

S5 SOLENOID

S6 SOLENOID

RED

BLK/ORN

M +

PUMP MOTOR

#6 RED

#6 BLK

WHT/YEL

LT GRN

LT BLU

BLK/WHT

BLU/ORN

LT BLU/ORN

LOCATED AT GRILLE

WHT

FASTON

#6 RED

VIO

BRN

#6 RED

LOCATED UNDER DASH

LT BLU/ORN

BLU/ORN

BLK/WHT

LT GRN

LT BLU

WHT/YEL

BRN/RED

BRN/GRN

RED

10AFB

RED

14 cartridge valves S6 & S5 & S4 and into the base end of the left cylinder causing it to extend.

6) The extending left cylinder pushes the hydraulic oil out of its rod end, through P/O check valve (A), solenoid cartridge valves S3 & S2 and back to the reservoir.

COIL CORD HARNESS

YEL

VIO

GRY

WHT

ORN

BLU

GRN

RED

TAN

BRN

BLK

BLADE MOVEMENT

CONTROL

REPRESENTATION

OF PRINTED

CIRCUIT BOARD

#6 BLK

MTR RLY

LEFT SIDE PLOW LAMP

ANGLE RIGHT

LOCATED AT VEHICLE FRONT RIGHT

Lit. No. 21857 June 15, 2003

ANGLE RIGHT – HYDRAULIC

RIGHT

LEFT

PRIMARY

RELIEF

VALVE

SECONDARY BLOCK ASSY.

3000 PSI

PRIMARY

RELIEF

VALVE

SECONDARY

RELIEF VALVE

3500 PSI

P/O

CHECK

VALVE

(C)

(D)

P/O

CHECK

VALVE

SECONDARY

RELIEF VALVE

3500 PSI

3000 PSI

PRIMARY BLOCK ASSY.

CONTROLLER MODE

CONTROLLER BUTTON

BLADE

MOVEMENT

MOTOR

SV08-2004

SV08-40

SV08-43

SV08-30

SV08-40

SV08-30

Lit. No. 21857

R/VEE

ANGLE

RIGHT

L/SCP

ANGLE

LEFT

WING

R/VEE *

RIGHT

RETRACT

RIGHT

EXTEND

L/SCP * L/SCP *

LEFT

RETRACT

LEFT

EXTEND

V / SCOOP

L/SCP

SCOOP

R/VEE

VEE

ALL

RAISE

ALL

LOWER

RAISE

LOWER

ON ON

LIFT

* NOTE - SEE BLADE MOVEMENT TEXT

FOR BUTTON OPERATION

P/O CHECK

VALVE

(A)

P/O

CHECK

VALVE

(B)

1750 PSI

PUMP

RELIEF

VALVE

June 15, 2003

ANGLE LEFT – ELECTRICAL

Blade Movement: Angle Left

Controller Mode: Straight Blade Mode

(Default)

Controller Button: L/SCP

System Response:

1) By pressing the controller button, the circuit board within the cab control completes the ground path for the electrical circuit.

PLOW ASSEMBLY

RIGHT SIDE PLOW LAMP

2) Electrical current flows through the motor relay, activating the pump motor, and solenoid cartridge valves S2 & S5, shifting both spools.

3) Hydraulic oil from the pump flows through solenoid cartridge valves

S2 & S3, P/O check valve (A) and into the rod end of the left cylinder causing it to retract.

4) Pressure within the hydraulic circuit causes P/O check valves

(B) & (C) to open.

5) The retracting left cylinder pushes the hydraulic oil out of its base end, through solenoid cartridge

COMPONENTS LOCATED FRONT LEFT OF VEHICLE

BRN

S1 SOLENOID

S2 SOLENOID

S3 SOLENOID

S4 SOLENOID

S5 SOLENOID

WHT/YEL

LT GRN

LT BLU

BLK/WHT

BLU/ORN

LT BLU/ORN

LOCATED AT GRILLE

WHT

VIO

BRN

LOCATED UNDER DASH

LT BLU/ORN

BLU/ORN

BLK/WHT

LT GRN

LT BLU

WHT/YEL

BRN/RED

BRN/GRN

S6 SOLENOID

RED

BLK/ORN

M +

#6 RED

PUMP MOTOR

#6 BLK

FASTON

#6 RED

RED

10AFB

RED

#6 BLK

MTR RLY

LEFT SIDE PLOW LAMP valves S4 & S5 & S6 and into the base end of the right cylinder causing it to extend.

6) The extending right cylinder pushes the hydraulic oil out of its rod end, through P/O check valve

(B), solenoid cartridge valve S2 and back to the reservoir.

COIL CORD HARNESS

YEL

VIO

GRY

WHT

ORN

BLU

GRN

RED

TAN

BRN

BLK

BLADE MOVEMENT

CONTROL

REPRESENTATION

ANGLE LEFT

LOCATED AT VEHICLE FRONT RIGHT

Lit. No. 21857 June 15, 2003

ANGLE LEFT – HYDRAULIC

RIGHT

LEFT

PRIMARY

RELIEF

VALVE

SECONDARY BLOCK ASSY.

3000 PSI

PRIMARY

RELIEF

VALVE

SECONDARY

RELIEF VALVE

3500 PSI

P/O

CHECK

VALVE

(C)

(D)

P/O

CHECK

VALVE

SECONDARY

RELIEF VALVE

3500 PSI

3000 PSI

PRIMARY BLOCK ASSY.

CONTROLLER MODE

CONTROLLER BUTTON

BLADE

MOVEMENT

MOTOR

SV08-2004

SV08-40

SV08-43

SV08-30

SV08-40

SV08-30

R/VEE

ANGLE

RIGHT

L/SCP

ANGLE

LEFT

WING

R/VEE *

RIGHT

RETRACT

R/VEE *

RIGHT

EXTEND

L/SCP *

LEFT

RETRACT

L/SCP *

LEFT

EXTEND

V / SCOOP

L/SCP

SCOOP

R/VEE

VEE

ALL

RAISE

ALL

LOWER

RAISE

LOWER

ON ON

LIFT

* NOTE - SEE BLADE MOVEMENT TEXT

FOR BUTTON OPERATION

Lit. No. 21857

P/O CHECK

VALVE

(A)

P/O

CHECK

VALVE

(B)

1750 PSI

PUMP

RELIEF

VALVE

June 15, 2003

RIGHT RETRACT – ELECTRICAL

Blade Movement: Right Retract

Controller Mode: Wing Mode

Controller Button: R/VEE

This button toggles between retract and extend in wing mode. Upon entering wing mode, the first activation of this button and every other activation thereafter retracts the wing. The second activation of

PLOW ASSEMBLY

LEFT SIDE PLOW LAMP

this button and every other activation thereafter extends the wing.

System Response:

1) By pressing the controller button, the circuit board within the cab control completes the ground path for the electrical circuit.

2) Electrical current flows through the motor relay activating the pump motor.

3) Hydraulic oil from the pump flows through solenoid cartridge valve

S2, P/O check valve (B) and into the rod end of the right cylinder causing it to retract.

COMPONENTS LOCATED FRONT LEFT OF VEHICLE

BRN

S1 SOLENOID

S2 SOLENOID

S3 SOLENOID

S4 SOLENOID

S5 SOLENOID

WHT/YEL

LT GRN

LT BLU

BLK/WHT

BLU/ORN

LT BLU/ORN

LOCATED AT GRILLE

WHT

VIO

BRN

LOCATED UNDER DASH

LT BLU/ORN

BLU/ORN

BLK/WHT

LT GRN

LT BLU

WHT/YEL

BRN/RED

BRN/GRN

S6 SOLENOID

RED

BLK/ORN

M +

#6 RED

PUMP MOTOR

#6 BLK

FASTON

#6 RED

RED

10AFB

RED

#6 BLK

MTR RLY

RIGHT SIDE PLOW LAMP

4) Pressure within the hydraulic circuit causes P/O check valves

(A) & (D) to open.

5) The retracting right cylinder pushes the hydraulic oil out of its base end, through solenoid cartridge valves S6 & S5, P/O check valve (D) and back to the reservoir.

COIL CORD HARNESS

YEL

VIO

GRY

WHT

ORN

BLU

GRN

RED

TAN

BRN

BLK

BLADE MOVEMENT

CONTROL

REPRESENTATION

CIRCUIT BOARD

RIGHT RETRACT

LOCATED AT VEHICLE FRONT RIGHT

Lit. No. 21857 June 15, 2003

RIGHT RETRACT – HYDRAULIC

RIGHT

LEFT

PRIMARY

RELIEF

VALVE

SECONDARY BLOCK ASSY.

3000 PSI

PRIMARY

RELIEF

VALVE

SECONDARY

RELIEF VALVE

3500 PSI

P/O

CHECK

VALVE

(C)

(D)

P/O

CHECK

VALVE

SECONDARY

RELIEF VALVE

3500 PSI

3000 PSI

PRIMARY BLOCK ASSY.

CONTROLLER MODE

CONTROLLER BUTTON

BLADE

MOVEMENT

MOTOR

SV08-2004

SV08-40

SV08-43

SV08-30

SV08-40

SV08-30

R/VEE

ANGLE

RIGHT

L/SCP

ANGLE

LEFT

WING

R/VEE *

RIGHT

RETRACT

R/VEE *

RIGHT

EXTEND

L/SCP *

LEFT

RETRACT

LEFT

EXTEND

V / SCOOP

L/SCP

SCOOP

R/VEE

VEE

ALL

RAISE

ALL

LOWER

RAISE

LOWER

ON ON

LIFT

* NOTE - SEE BLADE MOVEMENT TEXT

FOR BUTTON OPERATION

Lit. No. 21857

P/O CHECK

VALVE

(A)

P/O

CHECK

VALVE

(B)

1750 PSI

PUMP

RELIEF

VALVE

June 15, 2003

RIGHT EXTEND – ELECTRICAL

Blade Movement: Right Extend

Controller Mode: Wing Mode

Controller Button: R/VEE

This button toggles between retract and extend in wing mode.

Upon entering wing mode, the first activation of this button and every other activation thereafter retracts the wing. The second activation of this button and every other activation thereafter extends the wing.

System Response:

2) Electrical current flows through the motor relay, activating the

By pressing the controller button, the circuit board within the cab control completes the ground path for the electrical circuit.

pump motor, and solenoid cartridge valve S6, shifting its spool.

Hydraulic oil from the pump flows through solenoid cartridge valve

PLOW ASSEMBLY

RIGHT SIDE PLOW LAMP

S2, P/O check valve (B), solenoid cartridge valve S6 and into the base end of the right cylinder causing it to extend.

4) The extending right cylinder pushes the hydraulic oil out of its rod end. This oil mixes with the hydraulic oil from the pump, passes through solenoid cartridge valve S6 and into the base end of the extending right cylinder. This is called a

regenerative hydraulic circuit.

COMPONENTS LOCATED FRONT LEFT OF VEHICLE

BRN

S1 SOLENOID

S2 SOLENOID

S3 SOLENOID

S4 SOLENOID

S5 SOLENOID

WHT/YEL

LT GRN

LT BLU

BLK/WHT

BLU/ORN

LT BLU/ORN

LOCATED AT GRILLE

WHT

VIO

BRN

LOCATED UNDER DASH

LT BLU/ORN

BLU/ORN

BLK/WHT

LT GRN

LT BLU

WHT/YEL

BRN/RED

BRN/GRN

S6 SOLENOID

RED

BLK/ORN

M +

#6 RED

PUMP MOTOR

#6 BLK

FASTON

#6 RED

RED

10AFB

RED

#6 BLK

MTR RLY

LEFT SIDE PLOW LAMP

Even though both sides of the cylinder piston will experience the same hydraulic pressure, the cylinder will extend due to unequal force. The difference in area between the base end and rod end of the cylinder piston creates a greater force on the base end which extends the cylinder. Force = Pressure X

Surface Area.

Pressure within the hydraulic circuit causes P/O check valves

(A) & (D) to open.

COIL CORD HARNESS

YEL

VIO

GRY

WHT

ORN

BLU

GRN

RED

TAN

BRN

BLK

CONTROL

REPRESENTATION

OF PRINTED

CIRCUIT BOARD

BLADE MOVEMENT

RIGHT EXTEND

LOCATED AT VEHICLE FRONT RIGHT

Lit. No. 21857 June 15, 2003

RIGHT EXTEND – HYDRAULIC

RIGHT

LEFT

SECONDARY BLOCK ASSY.

3000 PSI

PRIMARY

RELIEF

VALVE

SECONDARY

RELIEF VALVE

3500 PSI

PRIMARY

RELIEF

VALVE

3000 PSI

P/O

CHECK

VALVE

(C)

(D)

P/O

CHECK

VALVE

SECONDARY

RELIEF VALVE

3500 PSI

PRIMARY BLOCK ASSY.

CONTROLLER MODE

CONTROLLER BUTTON

BLADE

MOVEMENT

MOTOR

SV08-2004

SV08-40

SV08-43

SV08-30

SV08-40

SV08-30

STRAIGHT BLADE

(DEFAULT)

R/VEE L/SCP

ANGLE

RIGHT

ANGLE

LEFT

WING

R/VEE *

RIGHT

RETRACT

R/VEE *

RIGHT

EXTEND

L/SCP *

LEFT

RETRACT

L/SCP *

LEFT

EXTEND

V / SCOOP

L/SCP

SCOOP

R/VEE

VEE

ON ON

ALL

RAISE

ALL

LOWER

RAISE

LOWER

ON ON

LIFT

* NOTE - SEE BLADE MOVEMENT TEXT

FOR BUTTON OPERATION

Lit. No. 21857

P/O CHECK

VALVE

(A)

P/O

CHECK

VALVE

(B)

1750 PSI

PUMP

RELIEF

VALVE

June 15, 2003

LEFT RETRACT – ELECTRICAL

Blade Movement: Left Retract

Controller Mode: Wing Mode

Controller Button: L/SCP

System Response:

this button and every other activation thereafter extends the wing.

By pressing the controller button, the circuit board within the cab control completes the ground path for the electrical circuit.

PLOW ASSEMBLY

RIGHT SIDE PLOW LAMP

2) Electrical current flows through the motor relay, activating the pump motor, and solenoid cartridge valve S2, shifting its spool.

3) Hydraulic oil from the pump flows through solenoid cartridge valves

S2 & S3, P/O check valve (A), and into the rod end of the left cylinder causing it to retract.

COMPONENTS LOCATED FRONT LEFT OF VEHICLE

BRN

S1 SOLENOID

S2 SOLENOID

S3 SOLENOID

S4 SOLENOID

S5 SOLENOID

LT BLU/ORN

S6 SOLENOID

RED

BLK/ORN

M +

#6 RED

PUMP MOTOR

#6 BLK

WHT/YEL

LT GRN

LT BLU

BLK/WHT

BLU/ORN

LOCATED AT GRILLE

WHT

FASTON

#6 RED

VIO

BRN

#6 RED

LOCATED UNDER DASH

LT BLU/ORN

BLU/ORN

BLK/WHT

LT GRN

LT BLU

WHT/YEL

BRN/RED

BRN/GRN

RED

10AFB

RED

#6 BLK

MTR RLY

LEFT SIDE PLOW LAMP

4) Pressure within the hydraulic circuit causes P/O check valves

(B) & (C) to open.

5) The retracting left cylinder pushes the hydraulic oil out of its base end, through solenoid cartridge valves S4 & S5, through P/O check valve (C) and back to the reservoir.

COIL CORD HARNESS

YEL

VIO

GRY

WHT

ORN

BLU

GRN

RED

TAN

BRN

BLK

CONTROL

REPRESENTATION

OF PRINTED

CIRCUIT BOARD

BLADE MOVEMENT

LEFT RETRACT

LOCATED AT VEHICLE FRONT RIGHT

Lit. No. 21857 June 15, 2003

LEFT RETRACT – HYDRAULIC

RIGHT

LEFT

PRIMARY

RELIEF

VALVE

SECONDARY BLOCK ASSY.

3000 PSI

PRIMARY

RELIEF

VALVE

SECONDARY

RELIEF VALVE

3500 PSI

P/O

CHECK

VALVE

(C)

(D)

P/O

CHECK

VALVE

SECONDARY

RELIEF VALVE

3500 PSI

3000 PSI

PRIMARY BLOCK ASSY.

CONTROLLER MODE

CONTROLLER BUTTON

BLADE

MOVEMENT

MOTOR

SV08-2004

SV08-40

SV08-43

SV08-30

SV08-40

SV08-30

STRAIGHT BLADE

(DEFAULT)

R/VEE L/SCP

ANGLE

RIGHT

ANGLE

LEFT

R/VEE *

RIGHT

RETRACT

WING

R/VEE *

L/SCP *

RIGHT

EXTEND

LEFT

RETRACT

L/SCP *

LEFT

EXTEND

V / SCOOP

L/SCP

SCOOP

R/VEE

VEE

ALL

RAISE

ALL

LOWER

RAISE

LOWER

ON ON

LIFT

* NOTE - SEE BLADE MOVEMENT TEXT

FOR BUTTON OPERATION

Lit. No. 21857

P/O CHECK

VALVE

(A)

P/O

CHECK

VALVE

(B)

1750 PSI

PUMP

RELIEF

VALVE

June 15, 2003

LEFT EXTEND – ELECTRICAL

Blade Movement: Left Extend

Controller Mode: Wing Mode

Controller Button: L/SCP

System Response:

2) Electrical current flows through the motor relay, activating the

By pressing the controller button, the circuit board within the cab control completes the ground path for the electrical circuit.

pump motor, and solenoid cartridge valves S2 & S4, shifting both spools.

Hydraulic oil from the pump flows through solenoid cartridge valves

PLOW ASSEMBLY

RIGHT SIDE PLOW LAMP

S2 & S3, P/O check valve (A), solenoid cartridge valve S4 and into the base end of the left cylinder causing it to extend.

4) The extending left cylinder pushes the hydraulic oil out of its rod end. This oil mixes with the hydraulic oil from the pump, passes through solenoid cartridge valve S4 and into the base end of the extending left cylinder. This is called a

regenerative hydraulic circuit.

COMPONENTS LOCATED FRONT LEFT OF VEHICLE

BRN

S1 SOLENOID

S2 SOLENOID

S3 SOLENOID

S4 SOLENOID

S5 SOLENOID

S6 SOLENOID

RED

BLK/ORN

M +

#6 RED

PUMP MOTOR

#6 BLK

WHT/YEL

LT GRN

LT BLU

BLK/WHT

BLU/ORN

LT BLU/ORN

LOCATED AT GRILLE

WHT

FASTON

#6 RED

VIO

BRN

#6 RED

LOCATED UNDER DASH

LT BLU/ORN

BLU/ORN

BLK/WHT

LT GRN

LT BLU

WHT/YEL

BRN/RED

BRN/GRN

RED

10AFB

RED

= Pressure X Surface Area.

Pressure within the hydraulic circuit causes P/O check valves

(B) & (C) to open.

COIL CORD HARNESS

YEL

VIO

GRY

WHT

ORN

BLU

GRN

RED

TAN

BRN

BLK

CONTROL

REPRESENTATION

OF PRINTED

CIRCUIT BOARD

BLADE MOVEMENT

MTR RLY

LEFT SIDE PLOW LAMP

#6 BLK

LEFT EXTEND

LOCATED AT VEHICLE FRONT RIGHT

Lit. No. 21857 June 15, 2003

LEFT EXTEND – HYDRAULIC

RIGHT

LEFT

PRIMARY

RELIEF

VALVE

SECONDARY BLOCK ASSY.

3000 PSI

PRIMARY

RELIEF

VALVE

SECONDARY

RELIEF VALVE

3500 PSI

P/O

CHECK

VALVE

(C)

3000 PSI

(D)

P/O

CHECK

VALVE

3500 PSI

SECONDARY

RELIEF VALVE

PRIMARY BLOCK ASSY.

CONTROLLER MODE

CONTROLLER BUTTON

BLADE

MOVEMENT

MOTOR

SV08-2004

SV08-40

SV08-43

SV08-30

SV08-40

SV08-30

STRAIGHT BLADE

(DEFAULT)

R/VEE

ANGLE

RIGHT

L/SCP

ANGLE

LEFT

WING

R/VEE * R/VEE *

RIGHT

RETRACT

RIGHT

EXTEND

L/SCP *

LEFT

RETRACT

LEFT

EXTEND

V / SCOOP

L/SCP

SCOOP

R/VEE

VEE

ALL

RAISE

ALL

LOWER

RAISE

LOWER

ON ON

LIFT

* NOTE - SEE BLADE MOVEMENT TEXT

FOR BUTTON OPERATION

Lit. No. 21857

P/O CHECK

VALVE

(A)

P/O

CHECK

VALVE

(B)

1750 PSI

PUMP

RELIEF

VALVE

June 15, 2003

SCOOP – ELECTRICAL

Blade Movement: Scoop

Controller Mode: V / Scoop Mode

Controller Button: L/SCP

System Response:

1) By pressing the controller button, the circuit board within the cab

2) control completes the ground path for the electrical circuit.

Electrical current flows through the motor relay, activating the pump motor, and solenoid

S1 SOLENOID

S2 SOLENOID

S3 SOLENOID

S4 SOLENOID

S5 SOLENOID

S6 SOLENOID

RED

BLK/ORN

M +

#6 RED

PUMP MOTOR

#6 BLK

RIGHT SIDE PLOW LAMP

WHT/YEL

LT GRN

LT BLU

BLK/WHT

BLU/ORN

LT BLU/ORN

PLOW ASSEMBLY

LEFT SIDE PLOW LAMP

4) cartridge valves S3 & S4 & S6, shifting the three spools.

Hydraulic oil from the pump flows through solenoid cartridge valve

S2 and into two separate hydraulic circuits.

Half of the oil flows through P/O check valve (B), solenoid cartridge valve S6 and into the base end of the right cylinder causing it to extend. The extending right cylinder pushes

LOCATED AT GRILLE

COMPONENTS LOCATED FRONT LEFT OF VEHICLE

WHT

VIO

FASTON

#6 RED

BRN

#6 RED the hydraulic oil out of its rod end.

This oil mixes with the hydraulic oil from the pump, passes through solenoid cartridge valve

S6 and into the base end of the extending right cylinder. This is called a regenerative hydraulic

circuit. Even though both sides of the cylinder piston will experience the same hydraulic pressure, the cylinder will extend due to unequal force. The difference in area between the

LOCATED UNDER DASH

LT BLU/ORN

BLU/ORN

BLK/WHT

LT GRN

LT BLU

WHT/YEL

BRN/RED

BRN/GRN

RED

10AFB

RED

COIL CORD HARNESS

YEL

VIO

GRY

WHT

ORN

BLU

GRN

RED

TAN

BRN

BLK

base end and rod end of the cylinder piston creates a greater force on the base end which extends the cylinder. Force =

Pressure X Surface Area.

5) The other half of the oil flows through solenoid cartridge valve

S3, P/O check valve (A), solenoid cartridge valve S4 and into the base end of the left cylinder causing it to extend. The extending left cylinder pushes the hydraulic oil out of its rod end.

CONTROL

This oil mixes with the hydraulic oil from the pump, passes through solenoid cartridge valve

S4 and into the

11 base end of the extending left cylinder. This is also a

regenerative hydraulic circuit.

REPRESENTATION

OF PRINTED

CIRCUIT BOARD

BLADE MOVEMENT

6) Pressure within the hydraulic circuit causes P/O check valves

#6 BLK

MTR RLY

SCOOP

LOCATED AT VEHICLE FRONT RIGHT

Lit. No. 21857 June 15, 2003

SCOOP – HYDRAULIC

RIGHT

LEFT

SECONDARY BLOCK ASSY.

3000 PSI

PRIMARY

RELIEF

VALVE

SECONDARY

RELIEF VALVE

3500 PSI

P/O

CHECK

VALVE

(C)

PRIMARY

VALVE

3000 PSI

(D)

P/O

CHECK

VALVE

3500 PSI

SECONDARY

RELIEF VALVE

PRIMARY BLOCK ASSY.

CONTROLLER MODE

CONTROLLER BUTTON

BLADE

MOVEMENT

MOTOR

SV08-2004

SV08-40

SV08-43

SV08-30

SV08-40

SV08-30

STRAIGHT BLADE

(DEFAULT)

R/VEE L/SCP

ANGLE

RIGHT

ANGLE

LEFT

WING

R/VEE * R/VEE *

RIGHT

RETRACT

RIGHT

EXTEND

L/SCP *

LEFT

RETRACT

LEFT

EXTEND

V / SCOOP

L/SCP

R/VEE

SCOOP

VEE

ON ON

ALL

RAISE

ALL

LOWER

RAISE

LOWER

LIFT

* NOTE - SEE BLADE MOVEMENT TEXT

FOR BUTTON OPERATION

Lit. No. 21857

P/O CHECK

VALVE

(A)

P/O

CHECK

VALVE

(B)

1750 PSI

PUMP

RELIEF

VALVE

June 15, 2003

VEE – ELECTRICAL

Blade Movement: Vee

Controller Mode: V / Scoop Mode

Controller Button: R/VEE

System Response:

1) By pressing the controller button, the circuit board within the cab control completes the ground path for the electrical circuit.

2) Electrical current flows through the motor relay, activating the pump motor, and solenoid cartridge valve S3, shifting its spool.

3) Hydraulic oil from the pump flows through solenoid cartridge valve

S2 and into two separate hydraulic circuits.

4) Half of the oil flows through P/O check valve (B) and into the rod end of the right cylinder causing it to retract.

PLOW ASSEMBLY

5) The other half of the oil flows through solenoid cartridge valve

S3, P/O check valve (A) and into the rod end of the left cylinder causing it to retract.

Pressure within the hydraulic circuit causes P/O check valves

The retracting right cylinder pushes the hydraulic oil out of its

COMPONENTS LOCATED FRONT LEFT OF VEHICLE

RIGHT SIDE PLOW LAMP

BRN

S1 SOLENOID

S2 SOLENOID

S3 SOLENOID

S4 SOLENOID

S5 SOLENOID

WHT/YEL

LT GRN

LT BLU

BLK/WHT

BLU/ORN

LT BLU/ORN

LOCATED AT GRILLE

WHT

VIO

BRN

LOCATED UNDER DASH

LT BLU/ORN

BLU/ORN

BLK/WHT

LT GRN

LT BLU

WHT/YEL

BRN/RED

BRN/GRN

S6 SOLENOID

RED

BLK/ORN

M +

PUMP MOTOR

#6 RED

#6 BLK

FASTON

#6 RED

RED

10AFB

RED base end, through solenoid cartridge valves S6 & S5, P/O check valve (D) and back to the reservoir.

8) The retracting left cylinder pushes the hydraulic oil out of its base end, through solenoid cartridge valves S4 & S5, through P/O check valve (C) and back to the reservoir.

COIL CORD HARNESS

YEL

VIO

GRY

WHT

ORN

BLU

GRN

RED

TAN

BRN

BLK

CONTROL

REPRESENTATION

OF PRINTED

CIRCUIT BOARD

BLADE MOVEMENT

MTR RLY

LEFT SIDE PLOW LAMP

#6 BLK

VEE

LOCATED AT VEHICLE FRONT RIGHT

Lit. No. 21857 June 15, 2003

VEE – HYDRAULIC

RIGHT

LEFT

PRIMARY

RELIEF

VALVE

SECONDARY BLOCK ASSY.

3000 PSI

PRIMARY

RELIEF

VALVE

SECONDARY

RELIEF VALVE

3500 PSI

P/O

CHECK

(C)

(D)

P/O

CHECK

VALVE

SECONDARY

RELIEF VALVE

3500 PSI

3000 PSI

PRIMARY BLOCK ASSY.

CONTROLLER MODE

CONTROLLER BUTTON

BLADE

MOVEMENT

MOTOR

SV08-2004

SV08-40

SV08-43

SV08-30

SV08-40

SV08-30

STRAIGHT BLADE

(DEFAULT)

R/VEE L/SCP

ANGLE

RIGHT

ANGLE

LEFT

WING

R/VEE *

RIGHT

RETRACT

R/VEE *

RIGHT

EXTEND

L/SCP *

LEFT

RETRACT

L/SCP *

LEFT

EXTEND

V / SCOOP

L/SCP

SCOOP

R/VEE

VEE

ALL

RAISE

ALL

LOWER

RAISE

LOWER

ON ON ON

ON ON

LIFT

* NOTE - SEE BLADE MOVEMENT TEXT

FOR BUTTON OPERATION

Lit. No. 21857

P/O CHECK

VALVE

(A)

P/O

CHECK

VALVE

(B)

1750 PSI

PUMP

RELIEF

VALVE

June 15, 2003

RAISE – ELECTRICAL

Blade Movement: Raise

Controller Mode: All Modes

Controller Button: Raise

System Response:

1) By pressing the controller button, the circuit board within the cab control completes the ground path for the electrical circuit.

2) Electrical current flows through the motor relay, activating the pump motor, and solenoid cartridge valves S2 & S3, shifting both spools.

3) Hydraulic oil from the pump flows through solenoid cartridge valves

S2 & S3, through the internal check valve in solenoid cartridge valve S1 into the base end of the lift cylinder causing it to extend.

S1 SOLENOID

WHT/YEL

LT GRN

LT BLU

S2 SOLENOID

S3 SOLENOID

BLK/WHT

BLU/ORN

S4 SOLENOID

S5 SOLENOID

LT BLU/ORN

S6 SOLENOID

RED

BLK/ORN

M +

#6 RED

PUMP MOTOR

#6 BLK

PLOW ASSEMBLY

RIGHT SIDE PLOW LAMP

COMPONENTS LOCATED FRONT LEFT OF VEHICLE

LOCATED AT GRILLE

WHT

FASTON

#6 RED

VIO

BRN

#6 RED

LOCATED UNDER DASH

LT BLU/ORN

BLU/ORN

BLK/WHT

LT GRN

LT BLU

WHT/YEL

BRN/RED

BRN/GRN

RED

10AFB

RED

LEFT SIDE PLOW LAMP

#6 BLK

MTR RLY

LOCATED AT VEHICLE FRONT RIGHT

COIL CORD HARNESS

YEL

VIO

GRY

WHT

ORN

BLU

GRN

RED

TAN

BRN

BLK

BLADE MOVEMENT

RAISE

CONTROL

REPRESENTATION

Lit. No. 21857 June 15, 2003

RAISE – HYDRAULIC

RIGHT

LEFT

PRIMARY

RELIEF

VALVE

SECONDARY BLOCK ASSY.

3000 PSI

PRIMARY

RELIEF

VALVE

SECONDARY

RELIEF VALVE

3500 PSI

P/O

CHECK

VALVE

(C)

(D)

P/O

CHECK

VALVE

SECONDARY

RELIEF VALVE

3500 PSI

3000 PSI

PRIMARY BLOCK ASSY.

CONTROLLER MODE

CONTROLLER BUTTON

BLADE

MOVEMENT

MOTOR

SV08-2004

SV08-40

SV08-43

SV08-30

SV08-40

SV08-30

STRAIGHT BLADE

(DEFAULT)

R/VEE L/SCP

ANGLE

RIGHT

ANGLE

LEFT

R/VEE *

RIGHT

RETRACT

R/VEE *

RIGHT

EXTEND

WING

L/SCP * L/SCP *

LEFT

RETRACT

LEFT

EXTEND

V / SCOOP

L/SCP

SCOOP

R/VEE

VEE

ALL

RAISE

ALL

LOWER

RAISE

LOWER

ON ON

LIFT

* NOTE - SEE BLADE MOVEMENT TEXT

FOR BUTTON OPERATION

Lit. No. 21857

P/O CHECK

VALVE

(A)

P/O

CHECK

VALVE

(B)

1750 PSI

PUMP

RELIEF

VALVE

June 15, 2003

LOWER – ELECTRICAL

Blade Movement: Lower / Float

Controller Mode: All Modes

Controller Button: Lower

System Response:

1) By pressing the controller button, the circuit board within the cab

PLOW ASSEMBLY control completes the ground path for the electrical circuit.

2) Electrical current flows through solenoid cartridge valves S1 & S3 shifting both spools.

3) The weight of the plow forces the lift cylinder to retract. The retracting lift cylinder pushes the hydraulic oil out of its base end, through solenoid cartridge valves

S1 & S3 & S2, and back to the reservoir.

COMPONENTS LOCATED FRONT LEFT OF VEHICLE

RIGHT SIDE PLOW LAMP

BRN

S1 SOLENOID

S2 SOLENOID

S3 SOLENOID

S4 SOLENOID

S5 SOLENOID

WHT/YEL

LT GRN

LT BLU

BLK/WHT

BLU/ORN

LT BLU/ORN

LOCATED AT GRILLE

WHT

VIO

BRN

LOCATED UNDER DASH

LT BLU/ORN

BLU/ORN

BLK/WHT

LT GRN

LT BLU

WHT/YEL

BRN/RED

BRN/GRN

S6 SOLENOID

RED

BLK/ORN

M +

#6 RED

PUMP MOTOR

#6 BLK

FASTON

#6 RED

RED

10AFB

RED

MTR RLY

LEFT SIDE PLOW LAMP

#6 BLK

LOCATED AT VEHICLE FRONT RIGHT

COIL CORD HARNESS

YEL

VIO

GRY

WHT

ORN

BLU

GRN

RED

TAN

BRN

BLK

BLADE MOVEMENT

LOWER

CONTROL

REPRESENTATION

OF PRINTED

CIRCUIT BOARD

Lit. No. 21857 June 15, 2003

LOWER – HYDRAULIC

RIGHT

LEFT

PRIMARY

RELIEF

VALVE

SECONDARY BLOCK ASSY.

3000 PSI

PRIMARY

RELIEF

VALVE

RELIEF VALVE

SECONDARY

3500 PSI

P/O

CHECK

VALVE

(C)

(D)

P/O

CHECK

VALVE

SECONDARY

RELIEF VALVE

3500 PSI

3000 PSI

PRIMARY BLOCK ASSY.

CONTROLLER MODE

CONTROLLER BUTTON

BLADE

MOVEMENT

MOTOR

SV08-2004

SV08-40

SV08-43

SV08-30

SV08-40

SV08-30

STRAIGHT BLADE

(DEFAULT)

R/VEE L/SCP

ANGLE

RIGHT

ANGLE

LEFT

WING

R/VEE *

RIGHT

RETRACT

R/VEE *

RIGHT

EXTEND

L/SCP *

LEFT

RETRACT

L/SCP *

LEFT

EXTEND

V / SCOOP

L/SCP

SCOOP

R/VEE

VEE

ALL

RAISE

ALL

LOWER

RAISE

LOWER

ON ON

LIFT

* NOTE - SEE BLADE MOVEMENT TEXT

FOR BUTTON OPERATION

Lit. No. 21857

P/O CHECK

VALVE

(A)

P/O

CHECK

VALVE

(B)

1750 PSI

PUMP

RELIEF

VALVE

June 15, 2003

HOLD IN RAISE POSITION – HYDRAULIC

Blade Movement: Hold in Raised

Position

Controller Mode: All Modes

Controller Button: None

System Response:

1) Hydraulic oil is trapped in the base end of the lift cylinder by the internal check valve in solenoid cartridge valve S1.

RIGHT

SECONDARY BLOCK ASSY.

3000 PSI

PRIMARY

RELIEF

VALVE

SECONDARY

RELIEF VALVE

3500 PSI

P/O

CHECK

VALVE

(C)

LEFT

PRIMARY

RELIEF

VALVE

3000 PSI

(D)

P/O

CHECK

VALVE

SECONDARY

RELIEF VALVE

3500 PSI

PRIMARY BLOCK ASSY.

CONTROLLER MODE

CONTROLLER BUTTON

BLADE

MOVEMENT

MOTOR

SV08-2004

SV08-40

SV08-43

SV08-30

SV08-40

SV08-30

STRAIGHT BLADE

(DEFAULT)

R/VEE

ANGLE

RIGHT

L/SCP

ANGLE

LEFT

R/VEE *

RIGHT

RETRACT

R/VEE *

RIGHT

EXTEND

WING

L/SCP * L/SCP *

LEFT

RETRACT

LEFT

EXTEND

V / SCOOP

L/SCP

SCOOP

R/VEE

VEE

ALL

RAISE

ALL

LOWER

RAISE

LOWER

LIFT

* NOTE - SEE BLADE MOVEMENT TEXT

FOR BUTTON OPERATION

P/O CHECK

VALVE

(A)

P/O

CHECK

VALVE

(B)

1750 PSI

PUMP

RELIEF

VALVE

Lit. No. 21857 June 15, 2003

STRIKING AN OBJECT WHILE PLOWING FORWARD – HYDRAULIC

Blade Movement: Striking an Object

While Plowing Forward

Controller Mode: All Modes

Controller Button: None

System Response:

1) Hydraulic oil is trapped in the base end of the right cylinder by the right primary relief valve, right secondary relief valve, and P/O check valve (D). Hydraulic oil is trapped in the base end of the left cylinder by left primary relief valve, left secondary relief valve, and P/O check valve (C).

2) When the plow contacts an object on the front side of either wing, the force of the impact increases the hydraulic pressure in the base end of one cylinder.

When the pressure exceeds

3000 psi, the cylinder’s primary relief valve opens allowing some of the hydraulic oil to move from the base end to rod end of the same cylinder.

3) Due to the unequal displacement of oil between the base and rod ends of the cylinder, hydraulic pressure will continue to increase. When the pressure exceeds 3500 psi the cylinder’s secondary relief valve opens allowing the remaining hydraulic oil back to the reservoir.

RIGHT

FORCE APPLIED

WHEN PUSHING

FORCE APPLIED

WHEN PUSHING

LEFT

PRIMARY

RELIEF

VALVE

SECONDARY BLOCK ASSY.

3000 PSI

PRIMARY

RELIEF

VALVE

3000 PSI

SECONDARY

RELIEF VALVE

3500 PSI

P/O

CHECK

VALVE

(C)

(D)

P/O

CHECK

VALVE

SECONDARY

RELIEF VALVE

3500 PSI

PRIMARY BLOCK ASSY.

CONTROLLER MODE

CONTROLLER BUTTON

BLADE

MOVEMENT

MOTOR

SV08-2004

SV08-40

SV08-43

SV08-30

SV08-40

SV08-30

STRAIGHT BLADE

(DEFAULT)

R/VEE

ANGLE

RIGHT

L/SCP

ANGLE

LEFT

WING

R/VEE *

RIGHT

RETRACT

R/VEE *

RIGHT

EXTEND

L/SCP *

LEFT

RETRACT

L/SCP *

LEFT

EXTEND

V / SCOOP

L/SCP

SCOOP

R/VEE

VEE

ALL

RAISE

ALL

LOWER

RAISE

LOWER

ON ON

LIFT

* NOTE - SEE BLADE MOVEMENT TEXT

FOR BUTTON OPERATION

P/O CHECK

VALVE

(A)

P/O

CHECK

VALVE

(B)

1750 PSI

PUMP

RELIEF

VALVE

Lit. No. 21857 June 15, 2003

STRIKING AN OBJECT WHILE BACK DRAGGING – HYDRAULIC

Blade Movement: Striking an Object

While Back Dragging

Controller Mode: All Modes

Controller Button: None

System Response:

1) Hydraulic oil is trapped in the rod end of the right cylinder by P/O check valve (B). Hydraulic oil is trapped in the rod end of the left cylinder by P/O check valve (A).

The hydraulic system does not provide pressure relief while back dragging.

RIGHT

FORCE APPLIED WHEN

BACK DRAGGING

FORCE APPLIED WHEN

BACK DRAGGING

LEFT

PRIMARY

RELIEF

VALVE

SECONDARY BLOCK ASSY.

3000 PSI

PRIMARY

RELIEF

VALVE

SECONDARY

RELIEF VALVE

3500 PSI

P/O

CHECK

VALVE

(C)

(D)

P/O

CHECK

VALVE

SECONDARY

RELIEF VALVE

3500 PSI

3000 PSI

PRIMARY BLOCK ASSY.

CONTROLLER MODE

CONTROLLER BUTTON

BLADE

MOVEMENT

MOTOR

SV08-2004

SV08-40

SV08-43

SV08-30

SV08-40

SV08-30

R/VEE

ANGLE

RIGHT

L/SCP

ANGLE

LEFT

WING

R/VEE * R/VEE *

RIGHT

RETRACT

RIGHT

EXTEND

L/SCP * L/SCP *

LEFT

RETRACT

LEFT

EXTEND

V / SCOOP

L/SCP R/VEE

SCOOP VEE

ON ON

ALL

RAISE

ALL

LOWER

RAISE

LOWER

LIFT

* NOTE - SEE BLADE MOVEMENT TEXT

FOR BUTTON OPERATION

P/O CHECK

VALVE

(A)

P/O

CHECK

VALVE

(B)

1750 PSI

PUMP

RELIEF

VALVE

Lit. No. 21857 June 15, 2003

HEADLAMPS – VEHICLE ONLY

PLOW ASSEMBLY

RIGHT SIDE PLOW LAMP

P/T SIG

HEADLAMP

PUR

BRN

PUR

BRN

BLK/ORN

(GROUND)

WHT (HIGH BEAM)

BLK (LOW BEAM)

S1 SOLENOID

WHT/YEL

S2 SOLENOID

LT BLU

S3 SOLENOID

LT GRN

S4 SOLENOID

BLK/WHT

S5 SOLENOID

BLU/ORN

S6 SOLENOID

LT BLU/ORN

RED

BLK/ORN

PUMP MOTOR

#6 RED

#6 BLK

PUR

BRN

WHT

BLK/ORN

BLK

HEADLAMP

BRN

RED

P/T SIG

BRN

T RED

LEFT SIDE PLOW LAMP

BLK

BLK/ORN

WHT

BRN

GRY

Lit. No. 21857

COMPONENTS LOCATED NEAR FRONT OF VEHICLE

BLU (GND)

TO VEHICLE

HEADLAMPS

RED (HIGH)

ORN (LOW)

TO RIGHT TURN

LAMP BULLET

TO LEFT TURN

LAMP BULLET

TO PARK

LAMP BULLET

PUR

GRY

BRN

WHT

HIGH

BEAM

87A

86 85

BRN

RED RED

WHT/YEL

BLK

LT GRN

LT BLU

BLK/ORN

WHT

BLK/WHT

BLU/ORN

GRY

PUR

BRN

LT BLU/ORN

#6 BLK

RED

#6 RED

WHT/YEL

BLK

LT GRN

LT BLU

BLK/ORN

WHT

BLK/WHT

BLU/ORN

GRY

PUR

BRN

LT BLU/ORN

#6 BLK

RED

#6 RED

RED RED

NOTE: Both high beam and low beam are shown

BLU (GND)

GRN (HIGH)

YEL (LOW)

FROM VEHICLE

HEADLAMP

CONNECTOR

LOW

BEAM

BLK

87A

86 85

BLK/ORN

87A

10AFB

RED

IGNITION

LT BLU/ORN

BLU/ORN

BLK/WHT

LT GRN

LT BLU

WHT/YEL

BRN/RED

RED

ORN/BLK

BRN/GRN

LOCATED UNDER DASH COIL CORD HARNESS

ORN/BLK

LOCATED NEAR BATTERY

#6 RED

MTR RLY

#6 RED

BRN/GRN

#6 BLK

BRN/RED

BLU

GRN

RED

TAN

BRN

BLK

YEL

VIO

GRY

WHT

ORN

** HAND HELD

CONTROL

REPRESENTATION

OF PRINTED

CIRCUIT BOARD

June 15, 2003

HIGH BEAM HEADLAMPS WITH PLOW CONNECTED TO VEHICLE

PLOW ASSEMBLY

RIGHT SIDE PLOW LAMP

P/T SIG

HEADLAMP

PUR

BRN

PUR

BRN

PUR

BRN

WHT

BLK/ORN

BLK

BLK/ORN

(GROUND)

WHT (HIGH BEAM)

BLK (LOW BEAM)

S1 SOLENOID

WHT/YEL

S2 SOLENOID

LT BLU

S3 SOLENOID

LT GRN

S4 SOLENOID

BLK/WHT

S5 SOLENOID

BLU/ORN

S6 SOLENOID

LT BLU/ORN

PUMP MOTOR

RED

BLK/ORN

#6 RED

#6 BLK

HEADLAMP

BRN

RED

P/T SIG

BRN

T RED

LEFT SIDE PLOW LAMP

BLK

BLK/ORN

WHT

BRN

GRY

Lit. No. 21857

COMPONENTS LOCATED NEAR FRONT OF VEHICLE

BLU (GND)

TO VEHICLE

HEADLAMPS

RED (HIGH)

ORN (LOW)

TO RIGHT TURN

LAMP BULLET

TO LEFT TURN

LAMP BULLET

TO PARK

LAMP BULLET

PUR

GRY

BRN

RED RED

WHT/YEL

BLK

LT GRN

LT BLU

BLK/ORN

WHT

BLK/WHT

BLU/ORN

GRY

PUR

BRN

LT BLU/ORN

#6 BLK

RED

#6 RED

WHT/YEL

BLK

LT GRN

LT BLU

BLK/ORN

WHT

BLK/WHT

BLU/ORN

GRY

PUR

BRN

LT BLU/ORN

#6 BLK

RED

#6 RED

RED RED

WHT

HIGH

BEAM

87A

86 85

BRN

LOW

BEAM

BLK

87A

86 85

BLK/ORN

BLU (GND)

GRN (HIGH)

YEL (LOW)

FROM VEHICLE

HEADLAMP

CONNECTOR

87A

10AFB

RED

IGNITION

LT BLU/ORN

BLU/ORN

BLK/WHT

LT GRN

LT BLU

WHT/YEL

BRN/RED

RED

ORN/BLK

BRN/GRN

LOCATED UNDER DASH COIL CORD HARNESS

ORN/BLK

LOCATED NEAR BATTERY

#6 RED

MTR RLY

#6 RED

BRN/GRN

#6 BLK

BRN/RED

YEL

VIO

GRY

WHT

ORN

BLU

GRN

RED

TAN

BRN

BLK

** HAND HELD

CONTROL

REPRESENTATION

OF PRINTED

CIRCUIT BOARD

June 15, 2003

LOW BEAM HEADLAMPS WITH PLOW CONNECTED TO VEHICLE

PLOW ASSEMBLY

RIGHT SIDE PLOW LAMP

P/T SIG

HEADLAMP

PUR

BRN

PUR

BRN

BLK/ORN

(GROUND)

WHT (HIGH BEAM)

BLK (LOW BEAM)

S1 SOLENOID

WHT/YEL

S2 SOLENOID

LT BLU

S3 SOLENOID

LT GRN

S4 SOLENOID

BLK/WHT

S5 SOLENOID

BLU/ORN

S6 SOLENOID

LT BLU/ORN

PUMP MOTOR

RED

BLK/ORN

M +

#6 RED

#6 BLK

PUR

BRN

WHT

BLK/ORN

BLK

HEADLAMP

BRN

RED

P/T SIG

BRN

T RED

LEFT SIDE PLOW LAMP

BLK

BLK/ORN

WHT

BRN

COMPONENTS LOCATED NEAR FRONT OF VEHICLE

BLU (GND)

TO VEHICLE

HEADLAMPS

RED (HIGH)

ORN (LOW)

TO RIGHT TURN

LAMP BULLET

TO LEFT TURN

LAMP BULLET

TO PARK

LAMP BULLET

PUR

GRY

BRN

RED RED

WHT/YEL

BLK

LT GRN

LT BLU

BLK/ORN

WHT

BLK/WHT

BLU/ORN

GRY

PUR

BRN

LT BLU/ORN

#6 BLK

RED

#6 RED

WHT/YEL

BLK

LT GRN

LT BLU

BLK/ORN

WHT

BLK/WHT

BLU/ORN

GRY

PUR

BRN

LT BLU/ORN

#6 BLK

RED

#6 RED

RED RED

WHT

HIGH

BEAM

87A

86 85

BRN

LOW

BEAM

BLK

87A

86 85

BLK/ORN

BLU (GND)

GRN (HIGH)

YEL (LOW)

FROM VEHICLE

HEADLAMP

CONNECTOR

87A

10AFB

RED

IGNITION

LT BLU/ORN

BLU/ORN

BLK/WHT

LT GRN

LT BLU

WHT/YEL

BRN/RED

RED

ORN/BLK

BRN/GRN

LOCATED UNDER DASH COIL CORD HARNESS

ORN/BLK

LOCATED NEAR BATTERY

#6 RED

MTR RLY

#6 RED

BRN/GRN

YEL

VIO

GRY

WHT

ORN

BLU

GRN

RED

TAN

BRN

BLK

#6 BLK

BRN/RED

Lit. No. 21857

** HAND HELD

CONTROL

REPRESENTATION

OF PRINTED

CIRCUIT BOARD

June 15, 2003

TROUBLESHOOTING GUIDE

Troubleshooting Guide Contents

General Diagnostic Table ............... 47

Packing Nut Adjustment ................ 50

Motor Test ...................................... 51

Motor and Motor Relay Test

Diagram ......................................... 52

Motor Relay Test ............................ 53

Vehicle Harness Test –

Motor Relay ................................... 54

Control Test ................................... 55

Pump Pressure Test ...................... 56

Solenoid Coil Activation Test .......... 57

Vehicle Harness Test –

Solenoid Coils ................................ 59

Hydraulic System Test ................... 60

Relief Valve Inspection and

Adjustment .................................... 63

Pilot Operated Check Valve

Inspection ...................................... 64

Individual Solenoid Coil Test .......... 64

Solenoid Cartridge Valve

Inspection ...................................... 65

Vehicle Headlamp Test .................. 66

Headlamp Test Diagram ................ 67

Plow Headlamp Test ...................... 68

Park/Turn Lamp Test ..................... 69

Introduction

This guide consists of a series of tables, diagrams, flow charts and other information. When used properly it will assist the mechanic in identifying and repairing faulty system components. Western highly recommends the use of the

MVP ® Electrical Tester as a timesaving option for electrical system diagnosis. When using this tester, refer to the supplied instruction manual for proper use of the tester.

Any malfunction of the MVP snowplow can be categorized as either mechanical, electrical or hydraulic. Mechanical issues are generally related to the blade wings,

A-frame, lift frame and mount components and are usually identified by visual inspection. Electrical and hydraulic issues can be difficult to trace to the component level and that is the purpose of this troubleshooting guide. Read and understand the

Theory of Operation before attempting troubleshooting.

How to Use the Troubleshooting

Guide

Because of the relative complexity of the MVP snowplow electrical and hydraulic systems, many variables need to be eliminated in order to obtain workable test procedures.

These variables translate into conditions listed before the tables or flow charts and must be satisfied before proceeding.

If the listed conditions are not met, the procedure can result in inaccurate results and wasted time.

In many cases, satisfying the listed conditions alone will solve the problem.

Go to the General Diagnostic

Table and satisfy the ten listed conditions. These conditions must be met before proceeding into the table or to any subsequent test.

Locate the condition in the table which best describes the problem and check possible causes and actions in the order listed.

Proceed to a service procedure, another condition, or a specific test as directed. All tests except the Hydraulic System Test use a flow chart format. To use these flow charts, first satisfy any listed conditions at the top of the page.

Then begin at the upper left square and proceed as directed.

Follow along sequentially through the table and tests, referring to the hydraulic and electrical schematics in the Theory of

Operation section and the component Identification and

Location diagrams. Eventually the problem will be pinpointed at the component level.

Electrical Testing

Read and understand the section describing electrical circuit operation in the Theory of Operation section. A simple 12V test light with a ground lead can be used for circuit testing.

When directed to check for 12 volts

(12V), ground the test lamp lead and probe the terminal. When asked to check for ground, attach the test lamp lead to +12V and probe the terminal.

Note that 12V is a nominal value. If using a voltmeter, actual voltage will vary with the vehicle and presence of loads in tested circuits.

Lit. No. 21857 June 15, 2003

GENERAL DIAGNOSTIC TABLE

Before using this General Diagnostic Table, or performing any tests, you must verify the following conditions:

Snowplow is attached to vehicle and all harnesses are connected.

Harness connector pins and terminals are free of corrosion and coated with dielectric grease, insuring good connections.

Vehicle battery and charging system are in good condition and battery connections are clean and tight.

14-Pin Connector

CAUTION

Fill the reservoir to the full level only. Do not overfill. Overfilling could damage the unit.

CAUTION

Do not mix different types of hydraulic fluid. Some fluids are not compatible and may cause performance problems and product damage.

Wire Color

Light Blue W ith Orange Stripe

Blue W ith Orange Stripe

Black W ith W hite Stripe

Light Green

Light Blue

W hite W ith Yellow Stripe

Brown W ith Red Stripe

Red

Orange W ith Black Stripe

Brown W ith Green Stripe

Pin No.

Hydraulic reservoir is filled to dipstick level with recommended fluid, when plow is in "vee" position and lift cylinder is fully retracted. See Product

Specifications.

There are no oil leaks from hoses, fittings, cylinders or the hydraulic unit.

All built up snow and ice is removed from the snowplow.

Vehicle harness wires are correctly installed in the 14 pin connector, located in the cab.

10 amp fuse in vehicle harness is good.

Ignition is turned on or engine is running.

10. The control is connected in the cab and turned on.

NOTE: Do not use a straight blade control with the adapter cable for these tests.

Lit. No. 21857 June 15, 2003

GENERAL DIAGNOSTIC TABLE

CONDITION

Motor does not run for any requested function.

Motor runs continuously.

Snowplow won’t raise — motor runs.

Snowplow raises slowly or partially — motor runs.

POSSIBLE CAUSE

Poor connections in vehicle or snowplow battery cables.

Motor worn or damaged or pump seized.

Motor relay inoperative.

Fault in vehicle wiring harness.

Malfunctioning controller.

Motor relay sticking or always energized.

Fault in vehicle harness wiring.

Malfunctioning controller.

Lift cylinder packing nut too tight.

Clogged pump filter (all functions are affected).

Worn or damaged pump.

Solenoid valve coils not energizing properly.

Hydraulic system malfunction.

Malfunctioning controller.

Quill adjusted in too far.

Lift cylinder packing nut too tight.

Clogged pump filter (all functions are affected).

Worn or damaged pump.

Malfunctioning controller.

In straight blade mode, snowplow angles slowly or partially

-or-

In wing mode, wings move slowly or partially — motor runs.

Air in angle cylinders.

Relief valves damaged or out of adjustment.

Pump filter clogged (all functions are affected).

Worn or damaged pump.

Solenoid valve coils not activating properly.

Hydraulic system malfunction.

Angle cylinders damaged or bypassing internally.

Snowplow will not lower or lowers slowly, or won't Quill adjusted in too far.

float Lift cylinder packing nut too tight.

Solenoid valve coils not activating properly.

Hydraulic system malfunction.

ACTION

Clean and re-establish connections.

Go to Motor Test.

Go to Motor Relay Test.

Go to Vehicle Harness Test - Motor Relay.

Go to Control Test.

Go to Motor Relay Test.

Go to Vehicle Harness Test - Motor Relay.

Go to Control Test.

Adjust lift cylinder packing nut.

Clean or replace filter, flush reservoir.

Go to Pump Pressure Test.

Go to Solenoid Coil Activation Test.

Go to Hydraulic System Test.

Go to Control Test.

Adjust quill out.

Adjust lift cylinder packing nut.

Clean or replace filter, flush reservoir.

Go to Pump Pressure Test.

Go to Control Test.

Cycle wings stop to stop to remove air.

Go to Relief Valve Inspection and Adjustment.

Clean or replace filter, flush reservoir.

Go to Pump Pressure Test.

Go to Solenoid Coil Activation Test.

Go to Hydraulic System Test.

Rebuild or replace angle cylinder.

Adjust quill out.

Adjust lift cylinder packing nut.

Go to Solenoid Coil Activation Test.

Go to Hydraulic System Test.

Lit. No. 21857 June 15, 2003

GENERAL DIAGNOSTIC TABLE

CONDITION POSSIBLE CAUSE

Snowplow lowers by itself or won’t stay in raised position

Solenoid valve coils not activating properly

Hydraulic system malfunction

Malfunctioning controller

Wings will not lock hydraulically or hold position.

Air in angle cylinders.

Relief valves damaged or out of adjustment.

P/O check valve stuck open

Solenoid coils not activating properly.

Hydraulic system malfunction.

Angle cylinders damaged or leaking internally.

Plow does not perform the selected function or performs a different function.

Vehicle harness 10 amp fuse blows.

ACTION

Go to Solenoid Coil Activation Test

Go to Hydraulic System Test

Go to Control Test.

Cycle wings stop to stop to remove air.

Go to Relief Valve Inspection & Adjustment.

Go to P/O Check Valve Inspection.

Go to Solenoid Coil Activation Test.

Go to Hydraulic System Test.

Repair or replace angle cylinders.

Hydraulic hose routing incorrect.

Solenoid valve coils not energizing properly.

Hydraulic system malfunction.

Verify correct hose installation. See Hose Routing diagram.

Go to Solenoid Coil Activation Test.

Go to Hydraulic System Test.

Red wire in plow harness going to solenoid valve coils is shorted to ground.

Red wire in vehicle harness going to terminal 3 of the vehicle battery connector is shorted to ground.

Repair wire or replace plow harness.

Repair wire or replace harness.

Red wire from fuse to terminal 8 of the 14-pin connector is shorted to ground.

Brown/green wire in vehicle harness going to motor relay primary is shorted to ground.

Malfunctioning controller.

Repair wire or replace harness.

Go to Control Test.

Control F1 fuse blows.

Control F2 fuse blows.

Vehicle accessory fuse blows.

Excessive load on vehicle electrical system while using snowplow.

Motor relay primary shorted internally.

Replace motor relay.

Solenoid valve coil S1, S2 or S3 shorted internally.

Go to Individual Coil Test.

Solenoid valve coil S4, S5 or S6 shorted internally.

Go to Individual Coil Test.

Circuit overloaded.

Consult vehicle owner’s manual for correct application of aftermarket electrical loads.

Quill adjusted in too far.

Lift cylinder packing nut too tight.

Worn or damaged motor or pump.

Adjust quill out.

Adjust lift cylinder packing nut.

Go to Pump Pressure Test.

Lit. No. 21857 June 15, 2003

GENERAL DIAGNOSTIC TABLE

CONDITION

Snowplow headlamps operate irregularly or not at all – snowplow attached.

-or-

Vehicle headlamps operate irregularly or not at all – snowplow removed.

Vehicle daytime running lamps (DRLs) do not work – snowplow removed.

POSSIBLE CAUSE

Burned out bulbs or corroded sockets.

Wires improperly connected to relays.

Headlamp relays inoperative.

Parking brake on.

Power in DRL circuit has been interrupted.

No output from DRL module.

ACTION

Replace bulbs, clean contacts.

Review and correct wire installation. See Headlamp

Test diagram.

Go to Plow Headlamp Test or Vehicle Headlamp Test.

Fully release parking brake.

Turn lamp and/or ignition switch on and off to cycle the

DRL circuitry.

Repair vehicle electrical system.

PACKING NUT ADJUSTMENT

NOTE: This adjustment applies to the lift cylinder only. Angle cylinders use gland nuts which are torqued to specifications.

Periodically verify the lift cylinder packing nut is tight. If the packing nut is loose or leakage appears when raising the plow, tighten the packing nut 1/4 turn maximum after you feel the packing nut contact the packing.

CAUTION

Do not overtighten the packing nut. Over-tightening affects the operation and life of the packing.

Packings not used for a period of time may show signs of oil weep.

This should stop after use.

NOTE: A small amount of leakage is necessary to properly lubricate the rod.

Lit. No. 21857 June 15, 2003

MOTOR TEST

WARNING

The driver shall keep bystanders clear of the blade during this test. Do not stand between the vehicle and the blade. During this test the right wing will retract. A moving or falling blade could cause personal injury.

Refer to the Motor and Motor Relay

Test Diagram.

Momentarily attach jumper cables from the battery to respective (+)

(-) motor terminals. Does motor run?

YES

Retest with jumper cable from battery (+) to (+) motor

terminal. Does motor run?

Repair or replace motor or pump.

Repair ground (black) wire in vehicle or plow battery cable.

YES

Momentarily attach (+) jumper cable between battery and motor side of motor relay secondary. Does motor run?

YES

Go to Motor

Relay Test.

Repair positive (red) wire in vehicle or plow battery cable.

Lit. No. 21857 June 15, 2003

MOTOR AND MOTOR RELAY TEST DIAGRAM

Small Red Wire

(Male)

Large Red Wire

Faston Connector

( )

( + )

Large Black

Wire

Vehicle Battery Cable

Large Red

Wire

Motor Relay

Primary

Terminals

Plow Battery Cable

Brown/Green Wire

Brown/Red Wire

Large Red Wire

Motor Relay

Secondary

Terminals

Lit. No. 21857 June 15, 2003

MOTOR RELAY TEST

WARNING

Perform motor test first to verify battery cables, motor and pump are good.

Refer to the Motor and Motor

Relay Test Diagram.

Motor does not run:

Attach a jum per cable across the m otor relay secondary term inals.

Does m otor run?

YES

Repair or replace (+) cable from battery to m otor relay.

Is there 12V at m otor relay prim ary term inal with brown/green wire?

Go to Vehicle Harness

Test - Motor Relay.

YES

Attach a ground jum per wire from battery (-) to relay prim ary term inal with brown/red wire.

Does m otor run?

YES

Replace m otor relay.

Go to Vehicle Harness

Test - Motor Relay.

Motor runs continuously:

Disconnect control in cab.

Does m otor continue to run?

YES

Lit. No. 21857

Go to Vehicle Harness

Test - Motor Relay.

Replace m otor relay.

June 15, 2003

VEHICLE HARNESS TEST - MOTOR RELAY

WARNING

Perform the Motor Test and

Motor Relay Test first.

Disconnect the control in the cab.

Refer to the 14-pin Connector diagram. Test the vehicle side of the connector in the cab as follows.

14-Pin Connector

Is there 12V at pin #8?

YES

Install a jumper wire between pins #8 and

#10. Does motor run?

YES

Is there 12V at motor relay primary terminal with brown/green wire?

YES

Is there 12V at pin #7?

YES

Remove jumper wire. Go to Control

Test.

Verify vehicle power source and 10a fuse in red wire. Repair red wire or replace harness.

Brown/red wire to motor relay is shorted to ground. Repair wire.

Brown/green wire to motor relay is open. Repair wire or replace harness.

Brown/red wire is open.

Repair wire or replace harness.

Lit. No. 21857 June 15, 2003

CONTROL TEST

CAUTION

Printed circuit board (PCB) is subject to damage from static electricity. Follow instructions below to safely handle PCB.

To safely handle PCB:

Place control on its side and remove top half of handle, leaving the PCB in lower half.

Remove PCB from housing by only touching the edges of the

PCB.

Touch a clean finger to metal part of fuse "F2".

PCB is now safe to handle as long as contact with it is maintained.

Test Procedure

1. Disconnect the control in the cab and remove to bench.

2. Remove control handle half to access internal components.

3. Refer to diagram for fuse location.

NOTE: Fuse F1 is for motor relay,

S1, S2 and S3 solenoid coils.

Fuse F2 is for S4, S5 and S6 solenoid coils.

Remove and test F1 with ohmmeter.

Is F1 good?

Replace F1. Go to condition “Control

F1 Fuse Blows” in General

Diagnostic Table.

Lit. No. 21857

FUSES

Remove and test F2 with ohmmeter.

Is F2 good?

Replace F2. Go to condition “Control

F2 Fuse Blows” in General

Diagnostic Table.

YES

Replace control or proceed by carefully disconnecting the white coil cord connector from the PC board. Test the coil cord harness for continuity between the connectors according to the electrical schematic. Note internal connections in the harness. Does continuity match schematic?

YES NO

Replace PC board

Replace coil cord harness.

June 15, 2003

PUMP PRESSURE TEST

Install a tee in-line with the lift cylinder hydraulic hose and attach a 3000 psi pressure gauge.

Raise the snowplow fully, hold the raise button and read the pump relief pressure.

Refer to Relief Valve

Identification and Location for valve location.

Is pump relief pressure

1750

± 100 psi?

YES

Is motor amp draw greater than 190 amps at pump relief?

YES NO

Is the pressure zero?

YES

Adjust pump relief clockwise1/4 turn to increase pressure. Did pressure change?

YES

Go to Solenoid Coil

Activation test

Adjust to 1750

± 100 psi.

Repair or replace motor

Go to

Hydraulic

System Test

Inspect pump relief valve for damaged components or contamination. Is pump relief valve OK?

YES

Go to Relief Valve

Inspection and

Adjustment.

Replace pump.

Remove pump.

Is pump O-ring damaged?

YES

Replace pump o-ring. Reassemble and adjust pressure

Lit. No. 21857 June 15, 2003

SOLENOID COIL ACTIVATION TEST

Disconnect the red (+) battery cable from the motor and isolate it.

Remove bolt attaching lift cylinder rod to lift arm. Tip the hydraulic unit forward and remove solenoid valve covers. Reattach cylinder to lift arm.

Verify wires are properly attached to solenoid coils. Refer to table below, Electrical Schematic and

Solenoid Cartridge Valve

Identification and Location.

Activate the control for each function and check for magnetic pull at all six solenoid valve coils.

Only the coils designated as

"ON" in the table below should activate for each function. After noting which coils are energized, proceed to the flow chart.

Solenoid Coil

12-PIN GRILL CONNECTOR PIN #

14-PIN CONNECTOR PIN #

WIRE COLOR

ANGLE RIGHT

ANGLE LEFT

RIGHT RETRACT *

RIGHT EXTEND *

LEFT RETRACT *

LEFT EXTEND *

SCOOP

VEE

RAISE

LOWER

1

6 WHITE/ YELLOW

4

5 LIGHT

BLUE

3

4 LIGHT

GREEN

ON

7

3 BLACK/

WHITE

8

2 BLUE/

ORANGE

ON

12

1 LT BLUE/

ORANGE

ON

ON ON

ON

*Coils activate on every other touch of the button in wing mode, beginning with retract when wing mode is first entered.

Lit. No. 21857 June 15, 2003

SOLENOID COIL ACTIVATION TEST

Do activated coils match the chart for all functions?

YES

Go to Hydraulic System Test.

Is there 12v at all six red wires attached to coils?

YES

Disconnect 3-pin battery cable harnesses at grill. Is there 12v at the small pin #3 of the vehicle battery harness?

YES

Go to Vehicle

Harness Test -

Solenoid Coils.

Repair small red wire in plow battery harness or plow harness.

Disconnect 12-pin harness connector at front of vehicle.

Are any coils activated?

YES

Is there 12v at each of pins

#1,3,4,7,8 and 12 of the plow harness 12-pin connector?

YES

Corresponding wire or solenoid coil is open. Go to Individual Coil Test.

Repair open wire or replace plow harness.

The wire between activated coil and 12-pin connector in plow harness is shorted to ground.

Repair wire.

Go to Vehicle Harness Test -

Solenoid Coils

Lit. No. 21857 June 15, 2003

VEHICLE HARNESS TEST — SOLENOID COILS

Perform solenoid coil activation test first.

Disconnect the red (+) battery cable from the motor and isolate it.

Connect all harness connectors at the grill.

Refer to the 14-pin Connector diagram for pin location.

14-Pin Connector

Disconnect the control in the cab. Are any solenoid coils activated? (Check for magnetic pull)

YES

Is there 12v at each of pins

#1,2,3,4,5 & 6 of 14-pin connector on vehicle harness?

YES

Is there 12v at any of pins #1,2,3,4,5 & 6?

YES

For pins which do not have

12v, corresponding wire in vehicle harness is open.

Repair wire or replace harness.

Corresponding wire in vehicle harness is shorted to ground.

Repair wire.

Is there ground at pin #9 of 14

Go to Control Test.

pin connector?

YES NO

Orange/black wire in vehicle harness is open.

Repair wire or replace harness.

Disconnect the Faston spade connector which connects the vehicle harness red wire to the small red wire in the vehicle battery cable. Is there 12v at the vehicle harness (female) side?

YES

Small red wire in vehicle battery cable is open. Repair wire or replace vehicle battery cable.

10 amp fuse is blown or red wire in vehicle harness is open.

Replace fuse, repair wire or replace harness.

Lit. No. 21857 June 15, 2003

HYDRAULIC SYSTEM TEST

This test consists of trying all the snowplow functions and comparing the snowplow reaction to the action requested in the following table. The table will pinpoint malfunctioning solenoid valves or closed p/o check valves accurately if only one component is malfunctioning. If the snowplow reaction for a given function is not listed in the table, there may be relief or p/o check valves which are stuck open or

ACTION REQUESTED

Angle Right contaminated, missing or damaged orings or backing rings on solenoid, relief or p/o check valves, or there may be two or more malfunctioning components. In this case, use the specific function hydraulic schematic and carefully inspect each component in the flow circuit. If contamination is evident in more than one component, the hydraulic unit, hoses and cylinders must be completely disassembled, inspected and cleaned.

PLOW REACTION

•

Angle Left

•

None

Perform Solenoid Coil Activation

Test first.

Verify hydraulic hose installation is correct. Refer to the Hose

Routing diagram.

Test all of the snowplow functions.

Inspect and clean or replace the suspected component. Refer to the MVP ® FloStat ® Parts

Diagram.

Angle Left

•

Right Extend

•

Right Retract

•

None

•

Angle Right

•

Raise

•

None

•

Left Extend

•

Left Retract

•

None

Refer to the sections following the table for inspection and adjustment of solenoid, cartridge valves, p/o check valves and relief valves.

IMPORTANT: When testing the

snowplow functions, be sure the control is not in “float.”

POSSIBLE CAUSE

S2 stuck shifted

S3 stuck shifted

Check valve B closed

Check valve A closed

S6 stuck shifted

S5 not shifted

S4 stuck shifted

S2 not shifted

S3 stuck shifted

Check valve A closed

Check valve B closed

S4 stuck shifted

S5 not shifted

S6 stuck shifted

Lit. No. 21857 June 15, 2003

HYDRAULIC SYSTEM TEST

ACTION REQUESTED

Right Retract

Right Extend

Left Retract

Left Extend

PLOW REACTION

•

Left Retract

•

Vee

•

None

•

Right Extend

•

Angle Right

•

Left Retract

•

Right Extend and Left Retract—wings not locked

•

None

•

Right Retract

•

Right Retract

•

Raise

•

None

•

Left Extend

•

Angle Left

•

Right Retract

•

Raise

•

None

•

Left Retract

POSSIBLE CAUSE

S2 stuck shifted

S3 stuck shifted

Check valve B closed

Check valve D closed

S6 stuck shifted

S5 stuck shifted

S2 stuck shifted

S3 stuck shifted

Check valve B closed

S6 not shifted

S2 not shifted

S3 stuck shifted

Check valve A closed

Check valve C closed

S4 stuck shifted

S5 stuck shifted

S2 not shifted

S3 stuck shifted

Check valve A closed

S4 not shifted

Lit. No. 21857 June 15, 2003

HYDRAULIC SYSTEM TEST

ACTION REQUESTED

Scoop

Vee

Raise

Hold Raised

Lower

PLOW REACTION

•

Raise

•

Right Extend—left wing floats

•

Right Extend

•

Left Extend

•

Right Extend and Left Retract—wings not locked

•

Left Extend

•

Raise

•

Right Retract

•

Left Retract

•

Left Extend and Right Retract—wings not locked

•

Left Retract

•

None

•

Left Retract and Right Extend—wings not locked

•

Vee

•

Left Retract

•

Raises very slowly

•

Lower

•

Lowers very slowly

•

None

POSSIBLE CAUSE

S2 stuck shifted

S3 not shifted

Check valve A closed

Check valve B closed

S4 not shifted

S6 not shifted

S2 stuck shifted

S3 not shifted

Check valve A closed

Check valve C closed

Check valve B closed

S4 stuck shifted

Check valve D closed

S5 stuck shifted

S6 stuck shifted

S2 not shifted

S3 not shifted

S1 stuck shifted

S1 stuck shifted or has faulty internal check valve

S2 stuck shifted

S3 not shifted

S1 not shifted

Lit. No. 21857 June 15, 2003

RELIEF VALVE INSPECTION AND ADJUSTMENT

Relief valve inspection

Remove the valve stem, ball, spacer and spring.

Look for broken or damaged parts, contamination or missing or damaged O-rings.

If OK, place ball on hard wood block, hold stem seat on ball and lightly strike stem with a hammer.

CAUTION

Be careful to strike stem squarely. You can bend stem if you do not strike it squarely.

Reassemble components into manifold block. Apply a light coat of anti-seize or grease to stem threads.

Adjustment

Adjust by tightening the relief valve stem as much as possible

(until spring is fully compressed)

Back off valve stem (rotate counterclockwise) the number of turns indicated in the chart.

Valve Manifold Block

Relief Valve

Pump Relief

Right or Left Cylinder

Primary Relief

Right or Left Cylinder

Secondary Relief

No. of Turns Backed Off

(CCW) From Fully Seated

2-1/2 - 2-3/4*

1-1/2 - 1-3/4**

1-1/4 - 1-1/2

Approximate

Relief Valve

Pressure (PSI)

1750

3000

3500

* Install a tee in line with the lift cylinder hydraulic hose and attach a

3000 psi gauge. Read the pressure at pump relief when holding the raise function button. Adjust pump relief valve to obtain 1750+/- 100 psi.

** Be certain the cylinder primary relief valve stem is backed out 1/4 turn farther than the secondary relief valve stem.

Spring

Spring Spacer

Ball

Valve Stem Seat

Valve Stem w/ O-rings

Lit. No. 21857 June 15, 2003

PILOT OPERATED CHECK VALVE INSPECTION

Remove check valve assembly from manifold block. Using long/ slender needle nosed pliers, remove the spool from the bore.

Using a plastic, aluminum or soft brass probe, push on the ball in the end of the check valve. It should move freely, then return to the closed position. If the ball sticks open or closed or binds, replace the check valve assembly. Clean, repair or replace as necessary.

Be sure replacement service p/o check valve assemblies have the letter ”V” stamped on the hex.

Inspect the spool for signs of wear or any

P/O Check

Valve damage indicating it is not shifting. Look for worn or damaged O-rings and repair or replace as necessary.

Re-oil all O-rings and reinstall the spool by holding the stem with the miniature needle nosed pliers and carefully inserting it fully into the bore. Install the check valve assembly and torque to 120 in-lb.

Check Valve

Assembly

O-ring

Spool

Back-up ring

O-ring

INDIVIDUAL SOLENOID COIL TEST

1. Remove both wires from coil terminals.

2. Attach an ohmmeter across the coil terminals.

3. A reading of approximately 7 ohms indicates the coil is OK.

NOTE: A good coil will draw approximately 1.5 amps.

Lit. No. 21857 June 15, 2003

SOLENOID CARTRIDGE VALVE INSPECTION

NOTE: S3, the SV08-43 cartridge valve is identical to the S2 and S5

SV08-40 cartridge valves in physical appearance. These two valves function differently internally and cannot be interchanged. The only way to tell them apart is by looking for the stamping “SV08-43” or “SV08-

40” on the side of the hex.

Remove coils from the solenoid cartridge valves and remove the valves from manifold. Look for visible contamination or damaged seals. Check for stuck spools with a plastic, aluminum, or soft brass probe by pushing on the spring loaded internal spool from the end of the valve. The spool should move freely through its entire travel.

NOTE: Using probe to move spool may shear contamination which was affecting spool movement.

Bench test the cartridge valve by installing a coil on the stem and applying 12V and ground to coil.

Watch through the side ports for internal spool travel.

If the cartridge valve spool is stuck or its travel is restricted, replace the cartridge. If the cartridge valve appears to be in good condition, clean it with parts cleaning solvent and dry with compressed air, being careful not to damage the seals. Check the spool travel again in case any internal contaminants were dislodged during cleaning.

Re-oil the cartridge valve seals and o-rings and reinstall the cartridge valve, torquing to 10 ft-lb.

Install the coils and torque retaining nuts to 4-5 ft-lb.

Apply 12V and ground to coil

NOTE: If contamination is seen in more than one component, it can be reasonably assumed that the entire system is contaminated and in order to perform a proper repair, the entire hydraulic unit must be disassembled and cleaned. The hoses and cylinders must also be disassembled and cleaned. The source of the contamination must be located and repaired before reassembly.

Cartridge valve marked on hex

Watch here

Probe here

Lit. No. 21857 June 15, 2003

VEHICLE HEADLAMP TEST

Verify correct wire installation to relays. See the Headlamp Test

Diagram.

Turn ignition and headlight switch on.

Disconnect all harnesses at the grill.

All bulbs must be good.

At each relay, is there 12v at terminal 30 with green (high beam) or yellow (low beam) wires?

YES

Apply 12v to relay terminal

87a with red (high beam) or orange (low beam) wires. Do vehicle headlamps come on?

YES

Unplug plug-in harness connectors at each vehicle headlamp. Is there 12v at the red wire (high beam) and orange wire (low beam)?

YES

Red or orange wires open in plug-in harness. Repair wire or replace harness.

Check vehicle output from headlight connector to plug-in harness. Repair vehicle system or open wires in plugin harness.

Remove 12v jumper from terminal 87a. Disconnect the black/orange wire from terminal 85 of both relays.

Do vehicle headlamps come

YES on?

Blue ground wire in plugin harness is open.

Repair wire or replace harness.

Black/orange wire in vehicle harness is shorted to ground.

Repair wire.

Replace relay

Lit. No. 21857 June 15, 2003

HEADLAMP TEST DIAGRAM

Existing Passenger-Side

Headlamp Connector

Existing Vehicle

Wire Harness

Plug-In Harness

Existing Driver-Side

Headlamp Connector

Plug-In Harness

Male Plug

Purple

Plug-In Harness

Headlamp Connectors

Passenger-Side

Turn Signal

Yellow

Purple

Driver-Side

Turn Signal

Purple

Black/

Orange

High Beam

Headlamp

Relay

White

Red

Orange

Green

Gray

Brown

Parking

Bullet Receptacle

Connector (Black)

Vehicle

Harness

Low Beam

Headlamp Relay

Purple

Black

Alternate Right Turn Signal

Connection Behind

Driver-Side Headlamp

Lit. No. 21857

Headlamp Relay Wiring Diagram

Low Beam Headlamp Relay

Black

87a

Brown

Black/

Orange

Yellow

High Beam Headlamp Relay

White

Brown

87a

Black/

Orange

Red

Green

June 15, 2003

PLOW HEADLAMP TEST

1. Verify correct harness and wire installation to the headlamp relays.

2. All bulbs must be good.

3. Connect all harnesses at the front of the vehicle .

4. Turn vehicle headlamp switch on.

For vehicles with Daytime

Running Lamps (DRLs), turn

At each headlamp relay, is there 12v at terminal 30 with green (high beam) or yellow

(low beam) wires?

NO ignition on. DRL equipped vehicles have a pink wire instead of a brown wire on relay terminal

86.

5. Refer to the Electrical Schematic,

Headlamp Test diagram and 12-

Pin Connector diagram.

12-Pin

Connector

YES

Apply (+) 12v to relay terminal 87 with white (high beam) or black

(low beam) wires. Do plow headlamps work?

YES

With (+) 12v applied at terminal 87, is there 12v at the black or white wires in the plow headlamp connectors at the bulb?

Low Beam

Headlamp

Ground

High Beam

Headlamp

1 2 3 4 5

7 8 9 10 11

Left Turn

Right Turn

Park

YES

Black/orange ground wire in plow harness is open. Repair wire or replace harness.

Corresponding wire is open in vehicle harness.

Repair wire or replace harness.

Check vehicle output from headlamp connector to plug-in harness. Repair vehicle electrical system or open wires in plug-in harness.

Is there 12v at each relay terminal 86 with brown or (DRL) pink wire?

YES

Disconnect 12-pin connector. Is there 12v at terminal #6 (high beam, white wire) or terminal #2

(low beam, black wire) on vehicle side?

YES

Corresponding wire is open in plow harness.

Repair wire or replace harness.

Check brown wire connection to vehicle park lamp circuit or

(DRL) pink wire connection to vehicle accessory wire or fusebox. Repair or replace open (DRL) pink or brown wire.

Attach a ground jumper wire to relay terminal 85 with black/orange wire.

Do plow lights come on?

YES

Remove jumper wire from relay.

Disconnect 12-pin connector. Attach ground jumper wire to terminal #5 on vehicle side. Is there 12v at terminal

#6 (high beam) or terminal #2 (low beam)?

Replace headlamp relay.

YES

Reconnect 12-pin connector. Attach ground jumper to (-) motor terminal. Do plow lights come on?

NO YES

Black/orange ground wire in vehicle harness is open.

Repair wire or replace harness.

Black/orange wire in plow harness is open.

Repair wire or replace harness

Poor ground between battery and motor (-) terminal. Repair vehicle or plow (-) battery cable.

Lit. No. 21857 June 15, 2003

PARK/TURN LAMP TEST

Verify plow park/turn (P/T) bulbs and contacts are good.

Turn parking lamps and ignition on.

Do vehicle park lam ps w ork?

Repair vehicle electrical system .

Connect all harnesses at the front of the vehicle.

Refer to the 12-Pin Connector diagram.

12-Pin

Connector

Low Beam

Headlamp

Ground

High Beam

Headlamp

1 2 3 4 5

7 8 9 10 11

Left Turn

Right Turn

Park

YES

Disconnect 12-pin connector.

Is there 12v at term inal #11 on the vehicle side?

Poor connection to vehicle circuit or open brown wire in vehicle harness. Repair wire or replace vehicle harness.

YES

Reconnect 12-pin connector.

Rem ove p/t bulbs from plow lights. Is there 12v at each brown wire term inal in the sockets?

Brown wire is open in plow harness. Repair wire or replace harness.

YES

Black/orange ground wire is open in plow harness.

Repair wire or replace harness.

Do vehicle turn signals w ork?

Repair vehicle electrical system .

YES

Disconnect 12-pin connector.

Is there 12v at term inals #10 for right turn and #9 for left turn?

Poor connection to vehicle circuit or open purple (right) or gray (left) wire in vehicle harness. Repair wire or replace harness.

YES

Reconnect 12-pin connector.

Rem ove p/t bulbs from plow lights.

Is there 12v at each red wire term inal in the sockets? (The purple and gray wires are spliced to red wires in the p/t sockets.)

Purple or gray wire is open in plow harness. Repair wire or replace harness.

YES

Black/orange ground wire is open in plow harness.

Repair wire or replace harness.

Lit. No. 21857 June 15, 2003

REMOVABLE SPRING TOOL

To Replace A Spring On The Blade, Follow The Instructions

Below.

CAUTION

Servicing the trip springs without special tools and knowledge could result in personal injury. See your authorized Western Products outlet for service.

Insert the threaded rod in through the hole in the channel weldment.

Be sure the threaded hole in the tab on the rod is nearest to the channel.

Place the assembly on to the top anchor above the spring as illustrated. Be sure to place the spring bar in between the tabs on the rod. Insert the 1/2 x 1-1/2"

Gr. 5 cap screw through the outside tab, through the hole in the spring bar, and tighten into the threaded hole.

Drop the 1/2" flat washer Gr. 8 over the threaded rod and fasten the nut to the threaded rod.

Tighten the nut until the spring bar is raised enough to insert the pin through the pin hole. Center the pin within the hole.

1/2" Flat Washer Gr. 8

1/2 x 1-1/2"

Channel

Cap Screw Gr. 5

1/2" Coupling

Nut

Loosen the nut to lower the spring bar. Remove the spring tool assembly by removing the

1/2" cap screw.

Remove the spring from the blade by removing the bolt from the bottom of the spring bar.

Insert the new spring with the spring bar up through the top anchor on the blade. Fasten the bottom of the spring bar to the anchor on the trip edge with the previously removed fasteners. Tighten.

1/4 x 1-1/4" Pin

Repeat steps 1 and 2 above.

Repeat step 3 above, except remove the pin from the spring bar.

Repeat step 4 above.

Rod

Lit. No. 21857 June 15, 2003

TERMINAL REMOVAL TOOL AND TERMINAL REPLACEMENT

To Use the Terminal Removal Tool Follow the Instructions

Below:

To Replace a Terminal Follow the Instructions Below:

Gently insert the open end of the tool into the desired socket compartment in the 14-pin connector housing as illustrated.

Push it in until it bottoms out in the housing.

Gently pull the wire that corresponds with the socket compartment out of the housing.

Continue until the desired number of wires have been removed from the housing.

To reinsert the terminal simply gently push the terminal into its proper compartment until it locks into place.

Remove the damaged or faulty terminal from the end of the wire.

Strip 3/16” of insulation off the end of the wire as illustrated.

Push the Solder-Type Terminal over the bared wire.

Using proper soldering techniques, solder the terminal to the wire. Apply solder only to the barrel of the terminal as illustrated.

Mounting Bracket

14-pin Connector Housing

Wire end

3/16" strip length

Solder-Type

Terminal

Terminal Removal Tool

Apply solder here only

Vehicle Harness

Lit. No. 21857 June 15, 2003

WESTERN PRODUCTS

P.O. BOX 245038

MILWAUKEE, WI 53224-9538

A DIVISION OF DOUGLAS DYNAMICS, L.L.C.

Copyright © 2003 Douglas Dynamics. L.L.C. All rights reserved. This material may not be reproduced or copied, in whole or in part, in any printed, mechanical, electronic, film or other distribution and storage media, without the written consent of Western Products. Authorization to photocopy items for internal or personal use by Western Products outlets or snowplow owner is granted.

Western Products reserves the right under its product improvement policy to change construction or design details and furnish equipment when so altered without reference to illustrations or specifications used. Western Products and the vehicle manufacturer may require and/or recommend optional equipment for snow removal. This product is manufactured under the following US patents: 4,999,935; 5,420,480; 5,806,213; 5,806,214; 6,253,470; RE 35,700; CAN 2,060,425; and other patents pending. Western Products offers a limited warranty on all snowplows and accessories. See separately printed page for this important information. The following are registered (

) and unregistered (™) trademarks of Douglas Dynamics, L.L.C.: FloStat

, MVP

, UniMount

, WESTERN

Lit. No. 21857

Printed in USA

June 15, 2003

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