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HEATING AND AIR CONDITIONING
PL
24 - 1
HEATING AND AIR CONDITIONING
TABLE OF CONTENTS
page
page
GENERAL INFORMATION
A/C APPLICATION TABLE . . . . . . . . . . . . . . . . . . . 2
HEATER AND AIR CONDITIONING CONTROL . . . 2
HEATER AND AIR CONDITIONING . . . . . . . . . . . . 2
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . 3
SAFETY PRECAUTIONS AND WARNINGS . . . . . . 4
DESCRIPTION AND OPERATION
A/C REFRIGERANT LINES . . . . . . . . . . . . . . . . . . 4
BLOWER MOTOR RESISTOR . . . . . . . . . . . . . . . . 5
COMPRESSOR . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
COMPRESSOR FRONT SHAFT SEAL . . . . . . . . . . 6
CONDENSATION DRAIN TUBE . . . . . . . . . . . . . . . 6
ENGINE COOLING SYSTEM REQUIREMENTS . . . 6
EVAPORATOR PROBE. . . . . . . . . . . . . . . . . . . . . . 6
HANDLING TUBING AND FITTINGS . . . . . . . . . . . 6
HIGH PRESSURE CUT OUT SWITCH. . . . . . . . . . 6
LOW PRESSURE CUT OFF SWITCH . . . . . . . . . . 6
SIDE WINDOW DEMISTERS . . . . . . . . . . . . . . . . 7
SYSTEM AIRFLOW . . . . . . . . . . . . . . . . . . . . . . . . 7
SYSTEM OIL LEVEL . . . . . . . . . . . . . . . . . . . . . . . 7
VACUUM CONTROL SYSTEM. . . . . . . . . . . . . . . . 8
DIAGNOSIS AND TESTING
A/C PERFORMANCE TEST . . . . . . . . . . . . . . . . . . 9
BLOWER MOTOR ELECTRICAL DIAGNOSIS . . . . 9
BLOWER MOTOR VIBRATION AND/OR
NOISE DIAGNOSIS . . . . . . . . . . . . . . . . . . . . . 11
COMPRESSOR NOISE DIAGNOSIS . . . . . . . . . . 11
EVAPORATOR PROBE TEST . . . . . . . . . . . . . . . . 11
EXPANSION VALVE. . . . . . . . . . . . . . . . . . . . . . . 11
HEATER PERFORMANCE TEST . . . . . . . . . . . . . 13
LOW PRESSURE CUT OFF SWITCH . . . . . . . . . 14
SYSTEM CHARGE LEVEL TEST . . . . . . . . . . . . . 14
VACUUM CONTROL SYSTEM. . . . . . . . . . . . . . . 15
SERVICE PROCEDURES
CHARGING A/C SYSTEM . . . . . . . . . . . . . . . . . . 17
EVACUATING REFRIGERANT SYSTEM. . . . . . . . 18
R-134a REFRIGERANT . . . . . . . . . . . . . . . . . . . . 19
SERVICING REFRIGERANT OIL LEVEL . . . . . . . 19
SYSTEM LEAK CHECKING . . . . . . . . . . . . . . . . . 20
REMOVAL AND INSTALLATION
A/C FILTER/DRIER . . . . . . . . . . . . . . . . . . . . . . . 20
A/C SERVICE PORT VALVE CORES . . . . . . . . . . 21
BLOWER MOTOR AND WHEEL ASSEMBLY. . . . 21
BLOWER MOTOR RESISTOR . . . . . . . . . . . . . . . 22
BLOWER MOTOR WHEEL . . . . . . . . . . . . . . . . . 22
COMPRESSOR . . . . . . . . . . . . . . . . . . . . . . . . . . 22
COMPRESSOR CLUTCH/COIL ASSEMBLY . . . . . 23
CONDENSATION DRAIN TUBE . . . . . . . . . . . . . . 25
CONDENSER. . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
DISCHARGE LINE . . . . . . . . . . . . . . . . . . . . . . . . 26
EVAPORATOR . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
EVAPORATOR PROBE. . . . . . . . . . . . . . . . . . . . . 26
EXPANSION VALVE. . . . . . . . . . . . . . . . . . . . . . . 27
HEATER CORE . . . . . . . . . . . . . . . . . . . . . . . . . . 28
HEATER HOSES . . . . . . . . . . . . . . . . . . . . . . . . . 28
HIGH PRESSURE CUT OUT SWITCH. . . . . . . . . 29
HIGH PRESSURE RELIEF VALVE . . . . . . . . . . . . 29
LIQUID LINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
LOW PRESSURE CUT OFF SWITCH . . . . . . . . . 29
MODE CONTROL CABLE . . . . . . . . . . . . . . . . . . 30
RECIRCULATION DOOR ACTUATOR . . . . . . . . . 31
SUCTION LINE . . . . . . . . . . . . . . . . . . . . . . . . . . 31
TEMPERATURE CONTROL CABLE . . . . . . . . . . . 32
UNIT HOUSING. . . . . . . . . . . . . . . . . . . . . . . . . . 32
DISASSEMBLY AND ASSEMBLY
HEATER-A/C HOUSING. . . . . . . . . . . . . . . . . . . . 34
ADJUSTMENTS
MODE CONTROL CABLE . . . . . . . . . . . . . . . . . . 34
TEMPERATURE CONTROL CABLE . . . . . . . . . . . 34
24 - 2
HEATING AND AIR CONDITIONING
PL
GENERAL INFORMATION
A/C APPLICATION TABLE
Item
Description
Notes
Vehicle
PL Neon
System
expansion valve
Total Refrigerant
Capacity
R134a
765 grams / 27 oz / 1.69 lbs
Total Oil Capacity
ND-8 PAG oil
180 ml / 6.10 oz
Compressor
Nippondenso 10S17
Freeze-up Control
Fin sensor-3 wire
input to PCM, evaporator mounted, cycles
clutch off below 34° F, cycles back on
above 45° F
Low psi Control
opens < 14 psi, resets > 38 psi
expansion valve mounted
High psi Control
opens > 470 psi, resets < 370 - 330 psi
compressor mounted switch
Control head
manual type
Mode Door
cable
Blend Air Door
cable
Fresh/Recirc door
vacuum actuator
Blower Motor
control head switched
resistor block
Cooling Fan
variable speed
PCM controlled ISO solid state fan relay
Control
relay
PCM
Draw
2.5 amps @ 12V
6 0.5V @ 70° F
Gap
0.014” - 0.0269
Clutch
DRB IIIT
Reads
TPS, RPM, A/C switch test, fin sensor
A/C & fan relays
Actuators
fan & clutch relays
HEATER AND AIR CONDITIONING CONTROL
HEATER AND AIR CONDITIONING
Both the heater-only and heater-A/C systems use a
combination of, electrical, cable, and vacuum controls. These controls provide the vehicle operator
with a number of setting options to help control the
climate and comfort within the vehicle. Refer to the
owner’s manual in the vehicle glove box for more
information on the features, use, and suggested operation of these controls.
The heater-only or heater-A/C control panel is located
to the right of the instrument cluster on the instrument
panel. The control panel contains rotary-type knobs.
There is a blower motor speed switch, mode control
switch, temperature control, and airflow control.
The heater-only or heater-A/C control panel cannot
be repaired. If faulty or damaged, the entire unit
must be replaced. The control knobs and the illumination lamps are available for service replacement.
All vehicles are equipped with a common heaterA/C housing assembly (Fig. 1). The system combines
air conditioning, heating, and ventilating capabilities
in a single unit housing mounted under the instrument panel. On heater-only systems, the evaporator
coil is omitted from the housing and replaced with an
air restrictor plate.
Outside air enters the vehicle through the cowl top
opening at the base of the windshield, and passes
through a plenum chamber to the heater-A/C system
blower housing. Air flow velocity can then be
adjusted with the blower motor speed selector switch
on the heater-A/C control panel. The air intake openings must be kept free of snow, ice, leaves, and other
obstructions for the heater-A/C system to receive a
sufficient volume of outside air.
HEATING AND AIR CONDITIONING
PL
24 - 3
GENERAL INFORMATION (Continued)
On air conditioned vehicles, the outside air intake
can be shut off by selecting the recirculation mode
(Recirc) with the mode control knob. This will operate a vacuum actuated recirculating air door that
closes off the outside fresh air intake and recirculates
the air that is already inside the vehicle.
The optional air conditioner for all models is
designed for the use of non-CFC, R-134a refrigerant.
The air conditioning system has an evaporator to cool
and dehumidify the incoming air prior to blending it
with the heated air. This air conditioning system
uses an evaporator probe to maintain minimum
evaporator temperature and prevent evaporator
freezing, and cycles the compressor clutch.
Fig. 1 Common Blend-Air HVAC (Heating,
Ventilation, Air Conditioning) System - Typical
1
2
3
4
5
6
7
–
–
–
–
–
–
–
TEMPERATURE BLEND/AIR DOOR
EVAPORATOR CORE
BLOWER
PANEL DEFROST DOOR
HEAT DEFROST DOOR
HEATER CORE
RECIRCULATING AIR DOOR
It is also important to keep the air intake openings
clear of debris because leaf particles and other debris
that is small enough to pass through the cowl plenum screen can accumulate within the heater-A/C
housing. The closed, warm, damp and dark environment created within the heater-A/C housing is ideal
for the growth of certain molds, mildews and other
fungi. Any accumulation of decaying plant matter
provides an additional food source for fungal spores,
which enter the housing with the fresh air. Excess
debris, as well as objectionable odors created by
decaying plant matter and growing fungi can be discharged into the passenger compartment during
heater-A/C system operation.
The heater and optional air conditioner are blendair type systems. In a blend-air system, a blend-air
door controls the amount of unconditioned air (or
cooled air from the evaporator on models with air
conditioning) that is allowed to flow through, or
around, the heater core. A temperature control knob
on the heater-A/C control panel determines the discharge air temperature by moving a cable, which
operates the blend-air door. This allows an almost
immediate manual control of the output air temperature of the system.
The mode control knob on the heater-only or heater-A/C control panel is used to direct the conditioned
air to the selected system outlets. The mode control
switch uses a cable to control the mode door, while
the recirculation air door is operated by a vacuum
actuator motor.
INTRODUCTION
Both the heater and the heater/air conditioning
systems share many of the same functioning components. This group will deal with both systems
together when component function is common, and
separately when they are not.
For proper operation of the instrument panel controls, refer to the Owner’s Manual provided with the
vehicle.
To service the heater core or evaporator, the unit
housing must be removed from the vehicle (Fig. 2).
Fig. 2 HVAC Unit Housing
1
2
3
4
5
6
7
–
–
–
–
–
–
–
AIR DISTRIBUTION
RECIRCULATION DOOR VACUUM ACTUATOR
AIR INLET
BLOWER MOTOR
EVAPORATOR PROBE CONNECTOR
CONTROL CABLES
VACUUM HARNESS
24 - 4
HEATING AND AIR CONDITIONING
PL
GENERAL INFORMATION (Continued)
SAFETY PRECAUTIONS AND WARNINGS
DESCRIPTION AND OPERATION
WARNING: WEAR EYE PROTECTION WHEN SERVICING THE AIR CONDITIONING REFRIGERANT
SYSTEM. SERIOUS EYE INJURY CAN RESULT
FROM EYE CONTACT WITH REFRIGERANT. IF EYE
CONTACT IS MADE, SEEK MEDICAL ATTENTION
IMMEDIATELY.
DO NOT EXPOSE REFRIGERANT TO OPEN
FLAME. POISONOUS GAS IS CREATED WHEN
REFRIGERANT IS BURNED. AN ELECTRONIC TYPE
LEAK DETECTOR IS RECOMMENDED.
LARGE AMOUNTS OF REFRIGERANT RELEASED
IN A CLOSED WORK AREA WILL DISPLACE THE
OXYGEN AND CAUSE SUFFOCATION.
THE EVAPORATION RATE OF REFRIGERANT AT
AVERAGE TEMPERATURE AND ALTITUDE IS
EXTREMELY HIGH. AS A RESULT, ANYTHING THAT
COMES IN CONTACT WITH THE REFRIGERANT
WILL FREEZE. ALWAYS PROTECT SKIN OR DELICATE OBJECTS FROM DIRECT CONTACT WITH
REFRIGERANT. R-134a SERVICE EQUIPMENT OR
VEHICLE A/C SYSTEM SHOULD NOT BE PRESSURE TESTED OR LEAK TESTED WITH COMPRESSED AIR.
SOME MIXTURES OF AIR and R-134a HAVE BEEN
SHOWN TO BE COMBUSTIBLE AT ELEVATED
PRESSURES. THESE MIXTURES ARE POTENTIALLY
DANGEROUS AND MAY RESULT IN FIRE OR
EXPLOSION CAUSING INJURY OR PROPERTY
DAMAGE.
ANTIFREEZE IS AN ETHYLENE GLYCOL BASE
COOLANT AND IS HARMFUL IF SWALLOWED OR
INHALED. SEEK MEDICAL ATTENTION IMMEDIATELY IF SWALLOWED OR INHALED. DO NOT
STORE IN OPEN OR UNMARKED CONTAINERS.
WASH SKIN AND CLOTHING THOROUGHLY AFTER
COMING IN CONTACT WITH ETHYLENE GLYCOL.
KEEP OUT OF REACH OF CHILDREN AND PETS.
DO NOT OPEN A COOLING SYSTEM WHEN THE
ENGINE IS AT RUNNING TEMPERATURE. PERSONAL INJURY CAN RESULT.
A/C REFRIGERANT LINES
CAUTION: The engine cooling system is designed
to develop internal pressure of 97 to 123 kPa (14 to
18 psi). Allow the vehicle to cool a minimum of 15
minutes before opening the cooling system. Refer
to Group 7, Cooling System.
DISCHARGE LINE
The discharge line is the line that goes from the
compressor to the condenser (Fig. 3). It has no serviceable parts except the rubber O-rings. If the line
is found to be leaking or is damaged it must be
replaced as an assembly.
Fig. 3 A/C Compressor Lines
1
2
3
4
5
–
–
–
–
–
CONDENSER LIQUID LINE
SUCTION LINE
COMPRESSOR MANIFOLD SCREWS
COMPRESSOR
DISCHARGE LINE
LIQUID LINE
The liquid line is the line that goes from the condenser to drier (Fig. 3). It has no serviceable parts
except the rubber O-rings. If the line is found to be
leaking or is damaged it must be replaced as an
assembly.
SUCTION LINE
The suction line is the large line that connects to
the expansion valve and goes to the compressor (Fig.
3). It also has a small line that goes to the filter/
drier. The suction line uses a gasket on the expansion valve side and rubber O-rings on all other
connections.
There are no serviceable parts on the suction line
other than the rubber O-rings and expansion valve
gasket. If the line is found to be leaking or is damaged it must be replaced as an assembly.
HEATING AND AIR CONDITIONING
PL
24 - 5
DESCRIPTION AND OPERATION (Continued)
A/C SERVICE PORT VALVE CORES
The A/C service port valve cores are serviceable
items (Fig. 4). The high side valve is located on the
filter-drier, and the low side valve is situated on the
suction line, near the washer fluid reservoir filler.
Fig. 5 Blower Motor Resistor Block
1 – RESISTOR BLOCK
2 – ELECTRICAL CONNECTOR
Fig. 4 A/C Service Port Valves
1 – A/C SERVICE PORTS
2 – FILTER/DRIER
BLOWER MOTOR RESISTOR
The blower motor resistor is located in the cowl, at
the base of the windshield (Fig. 5). There are two different resistor blocks depending on whether the vehicle is equipped with A/C or not. The blower motor
resistors will get hot when in use (Fig. 6). Do not
touch resistor block if the blower motor has been
running.
COMPRESSOR
The compressor used on this vehicle is a Nippondenso 10S17. This compressor uses an aluminum
swash plate, teflon coated pistons and aluminum
sleeveless cylinder walls.
NOISE
Excessive noise that occurs when the air conditioning is being used may be caused by:
• Loose bolts
• Mounting brackets
• Loose compressor clutch
• Excessive high refrigerant operating pressure
Fig. 6 Blower Motor Resistors
1 – RESISTOR BLOCK
2 – RESISTORS
Verify the following before compressor repair is
performed:
(1) Compressor drive belt condition
(2) Proper refrigerant charge
(3) Thermal expansion valve (TXV) operating correctly
(4) Head pressure is normal
24 - 6
HEATING AND AIR CONDITIONING
PL
DESCRIPTION AND OPERATION (Continued)
COMPRESSOR FRONT SHAFT SEAL
The compressor front shaft seal is not serviceable.
If a leak is detected at the shaft seal, the compressor
must be replaced as a unit.
CONDENSATION DRAIN TUBE
Condensation that accumulates in the evaporator
housing is drained from a tube through the dash and
on to the ground. This tube must be kept open to
prevent condensate water from collecting in the bottom of the housing.
The tapered end of the drain tube is designed to
keep contaminants from entering the heater A/C unit
housing. If the tube is pinched or blocked, condensate
cannot drain, causing water to back up and spill into
the passenger compartment. It is normal to see condensate drainage below the vehicle. If the tube is
damaged, it should be replaced.
ENGINE COOLING SYSTEM REQUIREMENTS
To maintain ample temperature levels from the
heating-A/C system, the cooling system must be in
proper working order. Refer to Group 0, Lubrication
and Maintenance or Group 7, Cooling System of this
manual.
The use of a bug screen is not recommended. Any
obstructions forward of the condenser can reduce the
effectiveness of the air conditioning system.
EVAPORATOR PROBE
The evaporator probe can be replaced without having to remove the unit housing from the vehicle.
The evaporator probe is located in the unit housing
and placed in the evaporator fins. The probe prevents
evaporator freeze-up. This is done by cycling the compressor clutch OFF when evaporator temperature
drops below freeze point. It cycles ON when the
evaporator temperature rises above freeze point. The
evaporator probe uses a thermistor probe in a capillary tube. The tube is inserted between the evaporator fins in the heater-A/C unit housing.
HANDLING TUBING AND FITTINGS
Kinks in the refrigerant tubing or sharp bends in
the refrigerant hose lines will greatly reduce the
capacity of the entire system. High pressures are produced in the system when it is operating. Extreme
care must be exercised to make sure that all connections are pressure tight. Dirt and moisture can enter
the system when it is opened for repair or replacement of lines or components. The refrigerant oil will
absorb moisture readily out of the air. This moisture
will convert into acids within a closed system.
CAUTION: The system must be completely empty
before opening any fitting or connection in the
refrigeration system. Open fittings with caution
even after the system has been emptied. If any
pressure is noticed as a fitting is loosened,
retighten fitting and evacuate the system again.
A good rule for the flexible hose lines is to keep
the radius of all bends at least 10 times the diameter of the hose. Sharper bends will reduce the flow
of refrigerant. The flexible hose lines should be
routed so they are at least 3 inches (80 mm) from
the exhaust manifold. Inspect all flexible hose lines
to make sure they are in good condition and properly routed.
The use of correct wrenches when making connections is very important. Improper wrenches or
improper use of wrenches can damage the fittings.
The internal parts of the A/C system will remain
stable as long as moisture-free refrigerant and
refrigerant oil is used. Abnormal amounts of dirt,
moisture or air can upset the chemical stability.
This may cause operational troubles or even serious damage if present in more than very small
quantities.
When opening a refrigeration system, have everything you will need to repair the system ready. This
will minimize the amount of time the system must
be opened. Cap or plug all lines and fittings as
soon as they are opened. This will help prevent the
entrance of dirt and moisture. All new lines and
components should be capped or sealed until they
are ready to be used.
All tools, including the refrigerant dispensing
manifold, the manifold gauge set, and test hoses
should be kept clean and dry.
HIGH PRESSURE CUT OUT SWITCH
The high pressure cut out switch is located on the
rear of the compressor (Fig. 7). It turns off the compressor if the system pressure exceeds 3240 kPa (470
psi).
LOW PRESSURE CUT OFF SWITCH
The Low Pressure Cut Off Switch (Fig. 8) monitors
the refrigerant gas pressure on the suction side of
the system. The low pressure cut off switch is located
on the expansion valve. The low pressure cut off
switch turns off voltage to the compressor clutch coil
when refrigerant gas pressure drops to levels that
could damage the compressor. The low pressure cut
out switch is a sealed factory calibrated unit. It must
be replaced if defective.
HEATING AND AIR CONDITIONING
PL
24 - 7
DESCRIPTION AND OPERATION (Continued)
SIDE WINDOW DEMISTERS
The demisters direct air from the unit housing
through the outlets located on the top corners of the
instrument panel. The demisters operate when the
mode selector is anywhere between floor and defrost
settings. Some air may be noticeable from the demister outlets when the mode selector is in the bilevel to
floor positions.
SYSTEM AIRFLOW
Fig. 7 High Pressure Cut Out Switch Location
1
2
3
4
–
–
–
–
DISCHARGE LINE
A/C COMPRESSOR
HIGH PRESSURE CUT OUT SWITCH
SUCTION LINE
The system pulls outside (ambient) air through the
cowl opening at the base of the windshield. Then it
goes into the plenum chamber above the unit housing. On air conditioned vehicles, the air passes
through the evaporator. Air flow can be directed
either through or around the heater core. This is
done by adjusting the blend-air door with the TEMP
control on the instrument panel. The air flow can
then be directed from the panel, floor and defrost
outlets in various combinations using the mode selector. There are 17 different mode selections possible.
Air flow velocity can be adjusted with the blower
speed selector switch on the instrument panel.
On A/C equipped vehicles the ambient air intake
can be controlled by opening and closing the recirculating air door. When placed in RECIRC, air that is
inside vehicle is removed continuously and recirculated through unit housing. Ambient air cannot be
controlled on vehicles without A/C. The system uses
outside air at all times.
The air conditioning compressor can be engaged by
turning the fan switch counterclockwise from the off
position. It can also be engaged by placing the mode
control in the mix to defrost positions. This will
remove heat and humidity from the air before it is
directed through or around the heater core.
SYSTEM OIL LEVEL
Fig. 8 Low Pressure Cut Off Switch
1
2
3
4
–
–
–
–
EXPANSION VALVE
LOW PRESSURE CUTOFF SWITCH
LIQUID LINE
SUCTION LINE
It is important to have the correct amount of oil in
the A/C system to ensure proper lubrication of the
compressor. Too little oil will result in damage to the
compressor. Too much oil will reduce the cooling
capacity of the system and consequently result in
higher discharge air temperatures.
24 - 8
HEATING AND AIR CONDITIONING
PL
DESCRIPTION AND OPERATION (Continued)
NOTE: The oil used in the compressor is ND8 PAG
R-134a refrigerant oil. Only refrigerant oil of the
same type should be used to service the system.
Do not use any other oil. The oil container should
be kept tightly capped until it is ready for use.
Tightly cap afterwards to prevent contamination
from dirt and moisture. Refrigerant oil will quickly
absorb any moisture it comes in contact with. Special effort must be used to keep all R-134a system
components moisture-free. Moisture in the oil is
very difficult to remove and will cause a reliability
problem with the compressor.
actuator is spring loaded so the door moves to the
Outside-air position when there is no vacuum supplied. The operation of the door can be viewed by
removing the blower motor and looking up into the
unit inlet.
It will not be necessary to check oil level in the
compressor or to add oil unless there has been an oil
loss. Oil loss at a leak point will be evident by the
presence of a wet, shiny surface around the leak.
REFRIGERANT OIL LEVEL CHECK
When an air conditioning system is first assembled, all components (except the compressor) are
refrigerant oil free. After the system has been
charged with R-134a refrigerant and operated, the oil
in the compressor is dispersed through the lines and
components. The evaporator, condenser, and filterdrier will retain a significant amount of oil, refer to
the Refrigerant Oil Capacities chart. When a component is replaced, the specified amount of refrigerant
oil must be added. When the compressor is replaced,
the amount of oil that is retained in the rest of the
system must be drained from the replacement compressor. When a line or component has ruptured and
oil has escaped, the compressor should be removed
and drained. The filter-drier must be replaced along
with the ruptured part. The oil capacity of the system, minus the amount of oil still in the remaining
components, can be measured and poured into the
suction port of the compressor.
Fig. 9 A/C Vacuum Line
1 – BRAKE POWER BOOSTER
2 – A/C VACUUM CHECK VALVE
3 – VACUUM HARNESS
REFRIGERANT OIL CAPACITIES
Refrigerant Oil Capacities
Component
ml
oz
Total System
180ml
6.1 oz
Filter-Drier
30 ml
1.0 oz
Condenser
30 ml
1.0 oz
Evaporator
59 ml
2.0 oz
All Refrigerant Lines
44 ml
1.5 oz
VACUUM CONTROL SYSTEM
The neon uses vacuum to operate only the recirculation door (Fig. 9). All other controls are cable.
When vacuum is supplied to the actuator, the door
moves to the Recirculation position (Fig. 10). The
Fig. 10 Recirculation Air Door Vacuum Actuator
1
2
3
4
5
6
–
–
–
–
–
–
OUTSIDE AIR/RECIRC DOOR HOUSING
VACUUM ACTUATOR LINKAGE
FOAM SEAL
RECIRC DOOR VACUUM ACTUATOR
DOOR LEVER
DOOR LEVER
HEATING AND AIR CONDITIONING
PL
24 - 9
DESCRIPTION AND OPERATION (Continued)
Normally, vacuum is supplied to the actuator by
placing the Circulation control knob in the Recirculation position. The Mode and the circulation control
are mechanically interlocked so the circulation control cannot be placed in the RECIRC position if the
mode control is at or between the mix and defrost
positions. Vacuum is supplied to the actuator only
when circulation control is at the RECIRC position.
If the circulation control is between the outside air
position and RECIRC position the system will be in
outside air. If the circulation control is in the
RECIRC position and the mode control is moved from
the floor to the defrost positions, the circulation control will move from the RECIRC position, to the outside air position beginning at the mix position. This
is to prevent window fogging.
DIAGNOSIS AND TESTING
A/C PERFORMANCE TEST
The air conditioning system is designed to remove
heat and humidity from the air entering the passenger compartment. The evaporator, located in the
heater A/C unit, is cooled to temperatures near the
freezing point. As warm damp air passes over the
fins in the evaporator, moisture in the air condenses
to water, dehumidifying the air. Condensation on the
evaporator fins reduces the evaporators ability to
absorb heat. During periods of high heat and humidity, an air conditioning system will be less effective.
With the instrument control set to RECIRC, only air
from the passenger compartment passes through the
evaporator. As the passenger compartment air dehumidifies, A/C performance levels rise.
PERFORMANCE TEST PROCEDURE
Review Safety Precautions and Warnings in this
group before proceeding with this procedure. Air temperature in test room and on vehicle must be 21° C
(70°F) minimum for this test.
NOTE: When connecting the service equipment
coupling to the line fitting, verify that the valve of
the coupling is fully closed. This will reduce the
amount of effort required to make the connection.
(1) Connect a tachometer and manifold gauge set.
(2) Set control to A/C, RECIRC, and PANEL, temperature lever on full cool and blower on high.
(3) Start engine and hold at 1000 rpm with A/C
clutch engaged.
(4) Engine should be warmed up with doors and
windows closed.
(5) Insert a thermometer in the left center A/C
outlet and operate the engine for five minutes. The
A/C clutch may cycle depending on ambient conditions.
(6) With the A/C clutch engaged, compare the discharge air temperature to the A/C Performance Temperatures chart.
(7) If the discharge air temperature fails to meet
the specifications in the performance temperature
chart. Refer to the Refrigerant Service Procedures for
further diagnosis.
A/C PERFORMANCE TEMPERATURES
Ambient Temperature
21°C (70°F)
26.5°C (80°F)
32°C (90°F)
37°C (100°F)
43°C (110°F)
Air Temperature at Left
Center Panel Outlet
1-8°C
(34-46°F)
3-9°C
(37-49°F)
4-10°C
(39-50°F)
6-11°C
(43-52°F)
7-18°C
(45-65°F)
Compressor Discharge
Pressure After the Filter
Drier
1034-1724 kPa
(150-250 PSI)
1517-2275 kPa
(220-330 PSI
1999-2620
kPa (290-380
PSI)
2068-2965
kPa (300-430
PSI)
2275-3421 kPa
(330-496 PSI)
103-207 kPa
(15-30 PSI)
117-221 kPa
(17-32 PSI)
138-241 kpa
(20-35 PSI)
172-269 kpa
(25-39 PSI)
207-345 kPa
(30-50 PSI)
Evaporator Suction
Pressure
BLOWER MOTOR ELECTRICAL DIAGNOSIS
Refer to the Blower Motor Electrical System Diagnosis chart (Fig. 11) in this section. Also refer to
Group 8W, Wiring Diagrams for more information.
24 - 10
HEATING AND AIR CONDITIONING
DIAGNOSIS AND TESTING (Continued)
Fig. 11 Blower Motor Electrical Diagnosis
PL
PL
HEATING AND AIR CONDITIONING
24 - 11
DIAGNOSIS AND TESTING (Continued)
BLOWER MOTOR VIBRATION AND/OR NOISE
DIAGNOSIS
The resistor block supplies the blower motor with
varied voltage (low and middle speeds) or battery
voltage (high speed).
CAUTION: Stay clear of the blower motor and resistor block (Hot). Do not operate the blower motor
with the resistor block removed from the heater-A/C
housing.
Refer to the Blower Motor Vibration/Noise chart
for diagnosis.
COMPRESSOR NOISE DIAGNOSIS
Excessive noise while the A/C is being used, can be
caused by loose mounts, loose clutch, or high operating pressure. Verify compressor drive belt condition,
proper refrigerant charge and head pressure before
compressor repair is performed.
If the A/C drive belt slips at initial start-up, it does
not necessarily mean the compressor has failed.
With the close tolerances of a compressor it is possible to experience a temporary lockup. The longer
the A/C system is inactive, the more likely the condition to occur.
This condition is the result of normal refrigerant
movement within the A/C system caused by temperature changes. The refrigerant movement may wash
the oil out of the compressor.
EVAPORATOR PROBE TEST
The work area and vehicle must be between 16° C
(60° F) and 32° C (90° F) when testing the switch.
(1) Disconnect the three wire connector from the
evaporator probe lead located behind the glove box
(Fig. 12).
(2) Start engine and set A/C to low blower motor
speed, panel, full cool, and RECIRC.
(3) Using a voltmeter, check for battery voltage
between Pin 1 and 2. If no voltage is detected, there
is no power to the switch. Check wiring and fuses.
Refer to Group 8W, Wiring Diagrams for circuit diagnosis.
(4) Using a voltmeter, check for battery voltage
between Pin 1 and Pin 3. If no voltage is detected,
there is no voltage from the Powertrain Control Module. Refer to Group 8W, Wiring Diagrams. If voltage
is OK, connect a jumper wire between Pin 1 and Pin
3. The compressor clutch should engage. If the clutch
engages, remove the jumper wire immediately and go
to Step 5. If the compressor clutch does not engage,
check the operation of the clutch and repair as necessary.
(5) If compressor clutch engages, connect the evaporator probe 3-way connector. The compressor clutch
should engage or cycle depending on evaporator temperature. If OK, go to Step 6. If not OK, replace the
clutch cycling switch.
(6) The engine running and the A/C set to:
• Blower motor on low speed
• Panel position
• Full cool
• RECIRC.
Close all doors and windows. Place a thermometer in
the center discharge vent.
(7) If the clutch does not begin to cycle off between
2° C to 7° C (35° F to 45° F), verify that the evaporator probe is fully installed and not loose in evaporator. If it is not properly installed, install probe and
retest outlet temperature. If the evaporator probe is
properly installed, replace the clutch cycling switch.
EXPANSION VALVE
NOTE: Expansion valve tests should be performed
after compressor tests.
Liquid CO2 is required to test the expansion
valve. It is available from most welding supply facilities. CO2 is also available from companies which
service and sell fire extinguishers.
Review Safety Precautions and Warnings in the
General Information section of this Group. The work
area and vehicle must be 21° to 27°C (70° to 85°F)
when testing expansion valve. To test the expansion
valve:
(1) Connect a charging station or manifold gauge
set to the refrigerant system service ports.
(2) Disconnect wire connector at low pressure cutoff switch (Fig. 13). Using a jumper wire, jump terminals inside wire connector boot.
(3) Close all doors, windows and vents to the passenger compartment.
(4) Set Heater-A/C control to A/C, full heat, floor,
RECIRC. and high blower.
(5) Start the engine and hold the idle speed (1000
rpm). After the engine has reached running temperature, allow the passenger compartment to heat up.
This will create the need for maximum refrigerant
flow into the evaporator.
(6) If the refrigerant charge is sufficient, discharge
(high pressure) gauge should read 965 to 2620 kPa
(140 to 380 psi). Suction (low pressure) gauge should
read 103 to 2417 kPa (15 to 35 psi). If system cannot
achieve proper pressure readings, replace the expansion valve. If pressure is correct, proceed with test.
24 - 12
HEATING AND AIR CONDITIONING
DIAGNOSIS AND TESTING (Continued)
BLOWER MOTOR NOISE/VIBRATION DIAGNOSIS
PL
HEATING AND AIR CONDITIONING
PL
24 - 13
DIAGNOSIS AND TESTING (Continued)
(8) Allow expansion valve to thaw. The low pressure gauge reading should stabilize at 103 to 241
kPa (15 to 35 psi). If not, replace expansion valve.
(9) When expansion valve test is complete, test
A/C overall performance. Refer to the Heater and A/C
Performance Test in this section. Remove all test
equipment before returning vehicle to use.
HEATER PERFORMANCE TEST
PRE-DIAGNOSTIC PREPARATIONS
Fig. 12 Evaporator Probe Harness Connector
1 – PIN #3
2 – PIN #2
3 – PIN #1
Review Safety Precautions and Warnings in this
group before performing the following procedures.
Check the coolant level, drive belt tension, vacuum
line connections, radiator air flow and fan operation.
Start engine and allow to warm up to normal temperature.
WARNING: DO NOT REMOVE RADIATOR CAP
WHEN ENGINE IS HOT, PERSONAL INJURY CAN
RESULT.
If vehicle has been run recently, wait 15 minutes
before removing cap. Place a rag over the cap and
turn it to the first safety stop. Allow pressure to
escape through the overflow tube. When the system
stabilizes, remove the cap completely.
MAXIMUM HEATER OUTPUT: TEST AND ACTION
Engine coolant is provided to the heater system by
two 16 mm (5/8 inch inside diameter) heater hoses.
With engine idling at normal running temperature,
set the control to maximum heat, floor, and high
blower setting. Using a test thermometer, check the
air temperature coming from the floor outlets, refer
to Temperature Reference chart.
TEMPERATURE REFERENCE CHART
Fig. 13 Expansion Valve & Low Pressure Cut-Off
Switch - Typical
1
2
3
4
–
–
–
–
EXPANSION VALVE
LOW PRESSURE CUT OFF SWITCH
SUCTION LINE
CONTROL HEAD
WARNING: PROTECT SKIN AND EYES FROM CONTACTING CO2 PERSONAL INJURY CAN RESULT.
(7) If suction side low pressure is within specified
range, freeze the expansion valve control head (Fig.
13) for 30 seconds. Use a super cold substance (liquid
CO2). Do not spray refrigerant on the expansion
valve for this test. Suction side low pressure should
drop to 34.5 kPa (5 psi) If not, replace expansion
valve.
Ambient
Temp.
Minimum
Floor
Outlet
Temp.
Celsius
Fahrenheit
Celsius
Fahrenheit
15.5°
60°
62.2°
144°
21.1°
70°
63.8°
147°
26.6°
80°
65.5°
150°
32.2°
90°
67.2°
153°
If the floor outlet air temperature is insufficient,
refer to Group 7, Cooling Systems for specifications.
Both heater hoses should be HOT to the touch (coolant return hose should be slightly cooler than the
supply hose). If coolant return hose is much cooler
than the supply hose, locate and repair engine coolant flow obstruction in heater system.
24 - 14
HEATING AND AIR CONDITIONING
PL
DIAGNOSIS AND TESTING (Continued)
POSSIBLE LOCATIONS OR CAUSE OF
OBSTRUCTED COOLANT FLOW
(1) Pinched or kinked heater hoses.
(2) Improper heater hose routing.
(3) Plugged heater hoses or supply and return
ports at cooling system connections, refer to Group 7,
Cooling System.
(4) Plugged heater core.
(5) Air locked heater core.
(6) If coolant flow is verified and outlet temperature is insufficient, a mechanical problem may exist.
POSSIBLE LOCATION OR CAUSE OF INSUFFICIENT
HEAT
(1) Obstructed cowl air intake.
(2) Obstructed heater system outlets.
(3) Blend-air door not functioning properly.
TEMPERATURE CONTROL
If temperature cannot be adjusted with the TEMP
lever on the control panel, the following could require
service:
(1) Blend-air door binding.
(2) Faulty blend-air door cable.
(3) Improper engine coolant temperature.
(4) Faulty Instrument Panel Control.
LOW PRESSURE CUT OFF SWITCH
The work area must not be below 21°C (70°F) to
test the compressor clutch circuit.
(1) With gear selector in park or neutral and park
brake set, start engine and allow to idle.
(2) Raise hood and disconnect low pressure cut off
switch connector boot.
(3) Using a suitable jumper wire, jump across the
terminals inside wire connector boot.
(4) If the compressor clutch does not engage, the
cycling clutch switch, wiring, relay, or fuse can be
defective. Refer to Group 8W, Wiring Diagrams.
(5) If clutch engages, connect manifold gauge set.
Read low pressure gauge. At pressure above 97 kPa
(14 psi) and above, low pressure out off switch will
complete the clutch circuit. If the low pressure gauge
reads below 140 kPa (20 psi), the system is low on
refrigerant charge or empty due to a leak. Refer to
Service Procedures, System Leak Checking in this
section.
(6) Install connector boot on switch and repeat
Step 3. If the clutch does not engage, replace the low
pressure cut off switch.
SYSTEM CHARGE LEVEL TEST
The procedure below should be used to check
and/or fill the refrigerant charge in the air conditioning system.
WARNING: AVOID BREATHING A/C REFRIGERANT
AND LUBRICANT VAPOR OR MIST. EXPOSURE MAY
IRRITATE EYES, NOSE AND THROAT. USE ONLY
APPROVED SERVICE EQUIPMENT MEETING SAE
REQUIREMENTS TO DISCHARGE R-134a SYSTEM.
IF ACCIDENTAL SYSTEM DISCHARGE OCCURS,
VENTILATE WORK AREA BEFORE RESUMING SERVICE.
R-134a SERVICE EQUIPMENT OR VEHICLE A/C
SYSTEM SHOULD NOT BE PRESSURE TESTED OR
LEAK TESTED WITH COMPRESSED AIR. MIXTURE
OF AIR and R-134a CAN BE COMBUSTIBLE AT ELEVATED PRESSURES. THESE MIXTURES ARE
POTENTIALLY DANGEROUS AND MAY RESULT IN
FIRE OR EXPLOSION CAUSING INJURY OR PROPERTY DAMAGE.
NOTE: The maximum amount of R-134a refrigerant
that the air conditioning system holds is 765 grams
(27 oz. or 1.69 lbs.)
It is recommended to use the gauges or reclaim/recycle equipment.
(1) Use a manifold gauge and check the liquid line
pressure.
(2) Attach a clamp-on thermocouple (P. S. E.
66-324-0014 or 80PK-1A) or equivalent to the liquid
line near the filter/drier.
(3) The vehicle must be in the following modes:
• Automatic transaxle in park or manual transaxle in neutral.
• Engine at idle
• A/C controls set to outside air
• Panel mode
• A/C ON full cool
• Blower motor ON high speed
• Vehicle windows closed
(4) Operate system for a couple of minutes to allow
the system to stabilize.
(5) Observe filter/drier pressure and Liquid line
temperature. Using the Charge Determination Chart
(Fig. 14) determine where the system is currently
operating. If the system is not in the proper range,
reclaim all the refrigerant and recharge per A/C
label.
HEATING AND AIR CONDITIONING
PL
24 - 15
DIAGNOSIS AND TESTING (Continued)
Fig. 14 Charge Determination Chart
VACUUM CONTROL SYSTEM
Use an adjustable vacuum test set (Special Tool
C-3707-B) and a suitable vacuum pump to test the
heater-A/C vacuum control system. With a finger
placed over the end of the vacuum test hose probe
(Fig. 15), adjust the bleed valve on the test set gauge
to obtain a vacuum of exactly 27 kPa (8 in. Hg.).
Release and block the end of the probe several times
to verify that the vacuum reading returns to the
exact 27 kPa (8 in. Hg.) setting. Otherwise, a false
reading will be obtained during testing.
Fig. 15 Adjust Vacuum Test Bleed Valve - Typical
1
2
3
4
–
–
–
–
VACUUM PUMP TOOL C-4289
VACUUM TEST SET C-3707
BLEED VALVE
PROBE
24 - 16
HEATING AND AIR CONDITIONING
PL
DIAGNOSIS AND TESTING (Continued)
HEATER-A/C VACUUM SYSTEM DIAGNOSIS
CONDITION
POSSIBLE CAUSES
CORRECTION
NO FORCED AIR IN
HEAT POSITION
1. Vacuum line pinched or
leaking.
2. Faulty heat defroster or
mode door.
3. Faulty selector switch.
4. Vacuum check valve.
1. Locate and repair vacuum leak or pinched line.
2. Test actuators and door operation. Repair as
necassary.
3. Test selector switch and replace if necessary.
4. Test check valve and replace if necessary.
NO FORCED AIR IN
PANEL POSITION
1. Vacuum line pinched or
leaking.
2. Faulty mode door.
3. Faulty selector switch.
4. Vacuum check valve.
1. Locate and repair vacuum leak or pinched line.
2. Test actuator and door operation. Repair as
necessary.
3. Test selector switch and replace if necessary.
4. Test check valve and replace if necessary.
NO FORCED AIR IN
DEFROST POSITION
1. Vacuum line pinched or
leaking.
2. Faulty heat, defroster, or
mode door.
3. Faulty selector switch.
4. Vacuum check valve.
1. Locate and repair vacuum leak or pinched line.
2. Test actuators and door operation. Repair as
necessary.
3. Test selector switch and replace if necessary.
4. Test check valve and replace if necessary.
ONE-WAY CHECK VALVE
(1) Disconnect the heater-A/C vacuum supply
(Black) tube in the engine compartment. This tube
passes through an opening in the dash panel.
(2) Remove the one-way vacuum check valve. The
valve is located on the (Black) vacuum supply hose at
the brake power booster.
(3) Connect the test set vacuum supply hose to the
heater side of the valve. When connected to this side
of the check valve, no vacuum should pass and the
test set gauge should return to the 27 kPa (8 in. Hg.)
setting. If OK, go to step Step 4. If not OK, replace
the faulty valve.
(4) Connect the test set vacuum supply hose to the
engine vacuum side of the valve. When connected to
this side of the check valve, vacuum should flow
through the valve without restriction. If not OK,
replace the faulty valve.
HEATER-A/C CONTROLS
The operation of the Circulation door can be
viewed by removing the blower motor and looking up
into the unit inlet. See Blower Motor Wheel and
Assembly removal and installation in this section for
service procedures.
(1) Connect the test set vacuum probe to the heater-A/C vacuum supply (Black) hose in the engine
compartment. Position the test set gauge so that it
can be viewed from the passenger compartment.
(2) Start with the Mode control in the Panel position and the Circulation control in the Outside-air
position.
(3) Move the Circulation control to the Recirculation position (the Circulation door should move into
the Recirculation position). After a short pause move
the Mode control to the Defrost position (the Circulation door should move to the Outside-air position).
The test gauge should return to the calibrated setting of 27 kPa (8 in. Hg.) after each selection is
made. If the gauge cannot achieve the calibrated setting, the vacuum circuit or a component has a leak.
(4) If the gauge achieves the calibrated setting but
the door does not move, there is either a pinched vacuum line or a failed actuator.
LOCATING VACUUM LEAKS
(1) Connect the test vacuum probe to the vehicles
(Black) supply hose. Position the vacuum test gauge
so it can be viewed from the passenger compartment.
(2) Place the Mode in the Panel position and the
Circulation control in the Recirculation position.
(3) Remove the center instrument panel bezel.
(4) Remove the center vent duct.
(5) Remove and block the Supply (Black) vacuum
line at the control. The test gauge should return to
the calibrated setting of 27 kPa (8 in. Hg). If not,
there is a leak in the Supply line.
(6) If there is no leak in the Supply line, reconnect
it to the Control and remove the Actuator Feed (Red)
line from the Control. Block the vacuum connection
on the Control from where the line was removed. The
test gauge should return to the calibrated setting of
27 kPa (8 in. Hg.). If not, there is a leak in the Control.
(7) If there is no leak in the Supply line or the
Control, reconnect the Actuator Feed (Red) line to the
control. Remove and block the Actuator Feed (Red)
line at the Actuator. The actuator vacuum port is
accessible behind and above the Glove Box. The test
PL
HEATING AND AIR CONDITIONING
24 - 17
DIAGNOSIS AND TESTING (Continued)
gauge should return to the calibrated setting of 27
kPa (8 in. Hg.). If not there is a leak in the Actuator
Feed line.
(8) If there is no leak in the Supply line, Control,
or the Actuator Feed line, the leak must be in the
Actuator itself. Connect the Vacuum hose from the
Vacuum Test Gauge directly to the Actuator to verify
the leak.
LOCATING PINCHED VACUUM LINES
The operation of the Circulation door can be
viewed by removing the blower motor and looking up
into the unit inlet. See Blower Motor Wheel and
Assembly removal and installation in this section for
service procedures.
(1) Connect the test vacuum probe to the vehicles
(Black) supply hose. Position the vacuum test gauge
so it can be viewed from the passenger compartment.
(2) Place the Mode in the Panel position and the
Circulation control in the Recirculation position.
(3) Remove the center instrument panel bezel.
(4) Remove the center vent duct.
(5) Remove the Supply (Black) vacuum line at the
control. The test gauge should drop indicating free
flow through the Supply line. If not, there is a blockage in the Supply line.
(6) If there is no blockage in the Supply line,
reconnect it to the Control. Remove the Actuator
Feed (Red) line from the Control. The test gauge
should drop indicating free flow through the Supply
line and Control. If not the vacuum switches on the
Control are not functioning.
(7) If there is no blockage in the Supply line or the
Control, reconnect the Actuator Feed (Red) line to the
control. Remove the Actuator Feed (Red) line at the
Actuator. The Actuator vacuum port is accessible
behind and above the Glove Box. The test gauge
should drop indicating free flow through the supply
line, Control, and the Actuator Feed line. If not,
there is a blockage in the Actuator Feed line.
(8) If there is no blockage in the Supply line, Control, or the Actuator Feed line, the Actuator must
have failed. Connect the Vacuum hose from the Vacuum Test Gauge directly to the Actuator to verify the
Actuator has failed.
SERVICE PROCEDURES
CHARGING A/C SYSTEM
PARTIAL CHARGE
This vehicle does not have a sight glass. It is not
possible to determine the amount of (R-134a) charge
in the system. Therefore it is necessary to completely
evacuate and recover the system, and then recharge
the system fully.
EVACUATION
Before adding refrigerant, all air must be evacuated from the system.
• Connect a manifold gauge set to the A/C service
ports (Fig. 16).
• Use a vacuum pump or charging station and
evacuate system to 95 kPa (28 inches Hg) for 30 minutes.
• Go to Charging A/C System below.
Fig. 16 A/C Service Ports
1 – A/C SERVICE PORTS
2 – FILTER/DRIER
CHARGING A/C SYSTEM
The procedure below should be used to fill the
refrigerant charge in the air conditioning system.
This A/C system does not have or use a sight glass to
check or charge the system.
WARNING: REVIEW SAFETY PRECAUTIONS AND
WARNINGS IN THIS GROUP BEFORE CHARGING
THE REFRIGERANT SYSTEM.
AVOID BREATHING A/C REFRIGERANT AND
LUBRICANT VAPOR OR MIST. EXPOSURE MAY
IRRITATE EYES, NOSE AND THROAT. USE ONLY
APPROVED SERVICE EQUIPMENT MEETING SAE
REQUIREMENTS TO DISCHARGE R-134a SYSTEM.
IF ACCIDENTAL SYSTEM DISCHARGE OCCURS,
VENTILATE WORK AREA BEFORE RESUMING SERVICE.
R-134a SERVICE EQUIPMENT OR VEHICLE A/C
SYSTEM SHOULD NOT BE PRESSURE TESTED OR
LEAK TESTED WITH COMPRESSED AIR. MIXTURE
OF AIR and R-134a CAN BE COMBUSTIBLE AT ELEVATED PRESSURES. THESE MIXTURES ARE
POTENTIALLY DANGEROUS AND MAY RESULT IN
FIRE OR EXPLOSION CAUSING INJURY OR PROPERTY DAMAGE.
24 - 18
HEATING AND AIR CONDITIONING
PL
SERVICE PROCEDURES (Continued)
CAUTION: Do not overcharge refrigerant system,
as excessive compressor head pressure can cause
noise and system failure.
After the system has been tested for leaks and
evacuated, a refrigerant (R-134a) charge can be
injected into the system.
NOTE: When connecting the service equipment
coupling to the line fitting, verify that the valve of
the coupling is fully closed. This will reduce the
amount of effort required to make the connection.
(1) If using a separate vacuum pump close all
valves before disconnecting pump. Connect manifold
gauge set to the A/C service ports (Fig. 16).
NOTE: The air conditioning system in this vehicle
holds (27 oz. or 1.69 lbs.) of R-134a refrigerant.
(2) Measure refrigerant (refer to capacities). Refer
to the instructions provided with the equipment
being used.
(3) Verify engine is shut off. Open the suction and
discharge valves. Open the charge valve to allow the
refrigerant to flow into the system. When the transfer of refrigerant has stopped, close the suction and
discharge valve.
(4) If all of the charge did not transfer from the
dispensing device, put vehicle controls into the following mode:
• Automatic transaxle in park or manual transaxle in neutral
• Engine idling at 700 rpm
• A/C control set in 100 percent outside air
• Panel mode
• Blower motor ON high speed
• Vehicle windows closed
If the A/C compressor does not engage, test the
compressor clutch control circuit and correct any failure. Refer to Group 8W, Wiring Diagrams.
(5) Open the suction valve to allow the remaining
refrigerant to transfer to the system.
WARNING: TAKE CARE NOT TO OPEN THE DISCHARGE (HIGH-PRESSURE) VALVE AT THIS TIME.
(6) Close all valves and test the A/C system performance.
(7) Disconnect the charging station or manifold
gauge set. Install the service port caps.
EVACUATING REFRIGERANT SYSTEM
NOTE: Special effort must be used to prevent moisture from entering the A/C system oil. Moisture in
the oil is very difficult to remove and will cause a
reliability problem with the compressor.
If a compressor designed to use R-134a refrigerant
is left open to the atmosphere for an extended period
of time. It is recommended that the refrigerant oil be
drained and replaced with new oil or a new compressor be used. This will eliminate the possibility of contaminating the refrigerant system.
If the refrigerant system has been open to the
atmosphere, it must be evacuated before the system
can be filled. Moisture and air mixed with the refrigerant will raise the compressor head pressure above
acceptable operating levels. This will reduce the performance of the air conditioner and damage the compressor. Moisture will boil at near room temperature
when exposed to vacuum. To evacuate the refrigerant
system:
NOTE: When connecting the service equipment
coupling to the line fitting, verify that the valve of
the coupling is fully closed. This will reduce the
amount of effort required to make the connection.
(1) Connect a suitable charging station, refrigerant
recovery machine, and a manifold gauge set with
vacuum pump (Fig. 17).
Fig. 17 Refrigerant Recovery Machine Hookup Typical
1 – LOW SIDE CONNECTOR
2 – HIGH SIDE CONNECTOR
3 – TO MANIFOLD SET
(2) Open the suction and discharge valves and
start the vacuum pump. The vacuum pump should
run a minimum of 45 minutes prior to charge to
eliminate all moisture in system. When the suction
gauge reads -88 kPa (- 26 in. Hg) vacuum or greater
for 45 minutes, close all valves and turn off vacuum
pump. If the system fails to reach specified vacuum,
the refrigerant system likely has a leak that must be
corrected. If the refrigerant system maintains specified vacuum for at least 30 minutes, start the vacuum pump, open the suction and discharge valves.
HEATING AND AIR CONDITIONING
PL
24 - 19
SERVICE PROCEDURES (Continued)
Then allow the system to evacuate an additional 10
minutes.
(3) Close all valves. Turn off and disconnect the
vacuum pump.
(4) The refrigerant system is prepared to be
charged with refrigerant.
R-134a REFRIGERANT
This vehicle uses a refrigerant called R-134a. It is
a non-toxic, non-flammable, clear colorless liquefied
gas.
R-134a refrigerant is not compatible with R-12
refrigerant in an air conditioning system. Even a
small amount of R-12 in a R-134a system could cause
compressor failure, refrigerant oil to sludge and/or
poor performance. Never add any other type of
refrigerant to a system designed to use R-134a
refrigerant. System failure will occur.
The high pressure service port is located on the
ffilter/drier. The low pressure service port is located
on the suction line near the strut tower.
When servicing a system, it is required that an air
conditioning charging recovery/recycling machine be
used (Fig. 18). Contact an automotive service equipment supplier for proper equipment. Refer to the
operating instructions provided with the equipment
for proper operation.
Fig. 19 Manifold Gauge Set - Typical
1
2
3
4
5
6
7
–
–
–
–
–
–
–
LOW PRESSURE GAUGE
HIGH PRESSURE GAUGE
VALVE
VACUUM/REFRIGERANT HOSE (YELLOW W/BLACK STRIP)
HIGH PRESSURE HOSE (RED W/BLACK STRIP)
LOW PRESSURE HOSE (BLUE W/BLACK STRIP)
VALVE
R-134a refrigerant requires a special type of compressor oil. When adding oil, make sure to use the oil
that is specified on the under hood label.
The use of R-134a will have a positive environmental impact due to it’s zero ozone depletion and low
global warming impact.
SERVICING REFRIGERANT OIL LEVEL
Fig. 18 Refrigerant Recovery/Recycling Station Typical
1 – R-134 REFRIGERANT RECOVERY MACHINE
A manifold gauge set (Fig. 19) must also be used in
conjunction with the charging and/or recovery/recycling device. Only use gauges that have not been
used for R-12. The service hoses on the gauge set
should have manual (turn wheel) or automatic back
flow valves at the service port connector ends. This
will prevent refrigerant R-134a from being released
into the atmosphere.
CAUTION: The refrigerant oil used in a R-134a A/C
system is unique. Use only oils which were
designed to work with R-134a refrigerant. The oil
designated for this vehicle is ND8 PAG (polyalkalene glycol).
Recovery/recycling equipment will measure the
lubricant being removed. This is the amount of lubricant to be added back to the system. If a new compressor is being installed, drain lubricant from old
compressor, measure the amount drained and discard
old lubricant. Drain the lubricant from the new compressor into a clean container. Return the amount of
lubricant measured from the old compressor, plus the
amount reclaimed from the system back into the new
compressor.
24 - 20
HEATING AND AIR CONDITIONING
PL
SERVICE PROCEDURES (Continued)
(1) Discharge refrigerant system using recovery/recycling equipment if charge is present.
(2) Disconnect refrigerant lines from A/C compressor. Cap the open lines to prevent moisture from
entering system.
(3) Remove compressor from vehicle.
(4) From suction port on top of compressor, drain
lubricant from compressor.
(5) Add system capacity minus the capacity of
components that have not been replaced. Refer to the
Lubricant Capacity Chart. Add lubricant through the
suction port on compressor. This is not to exceed 180
ml (6.10 oz.) in total.
(6) Install compressor and connect refrigerant
lines. Then evacuate and charge refrigerant system.
SYSTEM LEAK CHECKING
WARNING: R-134a SERVICE EQUIPMENT OR VEHICLE A/C SYSTEM SHOULD NOT BE PRESSURE
TESTED OR LEAK TESTED WITH COMPRESSED
AIR. MIXTURE OF AIR and R-134a CAN BE COMBUSTIBLE AT ELEVATED PRESSURES. THESE MIXTURES ARE POTENTIALLY DANGEROUS AND MAY
RESULT IN FIRE OR EXPLOSION CAUSING INJURY
OR PROPERTY DAMAGE.
AVOID BREATHING A/C REFRIGERANT AND
LUBRICANT VAPOR OR MIST. EXPOSURE MAY
IRRITATE EYES, NOSE AND THROAT. USE ONLY
APPROVED SERVICE EQUIPMENT MEETING SAE
REQUIREMENTS TO DISCHARGE R-134a SYSTEM.
IF ACCIDENTAL SYSTEM DISCHARGE OCCURS,
VENTILATE WORK AREA BEFORE RESUMING SERVICE.
If the A/C system is not cooling properly, determine
if the refrigerant system is fully charged with
R-134a. This is accomplished by performing a system
Charge Level-Check or Fill. If while performing this
test A/C liquid line pressure is less than 345 kPa (50
psi) proceed to Empty Refrigerant System Leak Test.
If liquid line pressure is greater than 345 kPa (50
psi) proceed to low refrigerant level leak test. If the
refrigerant system is empty or low in refrigerant
charge, a leak at any line fitting or component seal is
likely. A review of the fittings, lines and components
for oily residue is an indication of the leak location.
To detect a leak in the refrigerant system, perform
one of the following procedures as indicated by the
symptoms.
EMPTY REFRIGERANT SYSTEM LEAK TEST
(1) Evacuate the refrigerant system to the lowest
degree of vacuum possible (approx. 28 in Hg.). Determine if the system holds a vacuum for 15 minutes. If
vacuum is held, a leak is probably not present. If sys-
tem will not maintain vacuum level, proceed with
this procedure.
(2) Prepare a.284 Kg. (10 oz.) refrigerant charge to
be injected into the system.
(3) Connect and dispense.284 Kg. (10 oz.) of refrigerant into the evacuated refrigerant system.
(4) Proceed to Step 2 of Low Refrigerant Level
Leak Test.
LOW REFRIGERANT LEVEL LEAK TEST
(1) Determine if there is any (R-134a) refrigerant
in the system.
(2) Position the vehicle in a wind free work area.
This will aid in detecting small leaks.
(3) Bring the refrigerant system up to operating
temperature and pressure. This is done by allowing
the engine to run for five minutes with the system
set to the following:
• Transaxle in Park
• Engine Idling at 700 rpm
• A/C Controls Set in 100 percent outside air
• Blower switch in the high A/C position
• A/C in the ON position
• Open all windows
CAUTION: A leak detector designed for R-12 refrigerant (only) will not detect leaks in a R-134a refrigerant system.
(4) Shut off the vehicle and wait 2 to 7 minutes.
Then use an Electronic Leak Detector that is
designed to detect R-134a type refrigerant and search
for leaks. Fittings, lines, or components that appear
to be oily usually indicates a refrigerant leak. To
inspect the evaporator core for leaks, insert the leak
detector probe into the drain tube opening or a heat
duct. A R-134a dye is available to aid in leak detection, use only Chrysler approved refrigerant dye.
If a thorough leak check has been completed without indication of a leak, proceed to System Charge
Level.
REMOVAL AND INSTALLATION
A/C FILTER/DRIER
The filter/drier is mounted in a rubber grommet on
the right side of the engine compartment. The refrigerant must be recovered from the A/C system before
replacing the filter/drier assembly.
WARNING: THE REFRIGERATION SYSTEM MUST
BE COMPLETELY RECOVERED BEFORE PROCEEDING WITH THIS OPERATION.
HEATING AND AIR CONDITIONING
PL
24 - 21
REMOVAL AND INSTALLATION (Continued)
REMOVAL
(1)
(2)
from
(3)
Disconnect liquid line from filter/drier.
Disconnect liquid line on suction line assembly
filter/drier.
Pull filter/drier out of rubber grommet.
INSTALLATION
For installation, reverse the above procedures.
A/C SERVICE PORT VALVE CORES
REMOVAL
(1) Remove the valve caps (Fig. 4).
(2) Using a R-134a refrigerant recovery machine,
Remove the refrigerant from A/C system.
(3) Using a standard valve core tool, remove the
valve core. Be careful to prevent any dirt/debris
from entering the valve core opening or getting
on the replacement valve core.
Fig. 20 Blower Motor Retaining Screws
1 – BLOWER MOTOR
2 – BLOWER MOTOR RETAINING SCREWS
3 – BLOWER MOTOR WIRING
INSTALLATION
(1) When assembling the new valve core into the
port, the core should be oiled with clean ND8 PAG
compressor oil.
CAUTION: A valve that is not fully seated can lead
to damage to the valve during evacuation and
charge. This can result in system refrigerant discharge while uncoupling the charge adapters.
(2) Install valve core into port.
(3) Evacuate and charge the A/C system.
(4) Install the valve caps.
WITHOUT AIR CONDITIONING
REMOVAL
(1) Disconnect blower motor wiring connector.
(2) Grasp the blower motor while pulling down
tab. Turn approximately 1/8 turn counterclockwise
and remove blower motor assembly from unit housing (Fig. 21).
INSTALLATION
For installation, reverse the above procedures.
BLOWER MOTOR AND WHEEL ASSEMBLY
The blower motor is located on the bottom right
side of the unit housing. The blower motor can be
removed from the vehicle without having to remove
the unit housing assembly.
WITH AIR CONDITIONING
REMOVAL
(1) Remove right side scuff plate.
(2) Pull back carpet.
(3) Disconnect blower motor wiring connector.
(4) Remove blower motor retaining screws, and
lower blower motor assembly from unit housing (Fig.
20).
INSTALLATION
For installation, reverse the above procedures.
Fig. 21 Blower Motor Removal
1 – BLOWER MODULE
2 – BLOWER MOTOR
24 - 22
HEATING AND AIR CONDITIONING
PL
REMOVAL AND INSTALLATION (Continued)
BLOWER MOTOR RESISTOR
REMOVAL
CAUTION: Stay clear of the blower motor and resistor block (Hot). Do not operate the blower motor
with the resistor block removed.
The A/C compressor may be unbolted and repositioned without discharging the refrigerant system.
Discharging is not necessary if removing the compressor clutch/coil assembly, engine, cylinder head, or
alternator.
REMOVAL
(1)
(2)
(3)
(Fig.
Remove windshield wipers.
Remove cowl top screen.
Disconnect the resistor block wiring connector
22).
WARNING: REFRIGERANT PRESSURES REMAIN
HIGH EVEN THOUGH THE ENGINE MAY BE
TURNED OFF. DO NOT TWIST OR KINK THE
REFRIGERANT LINES WHEN REMOVING A FULLY
CHARGED COMPRESSOR. SAFETY GLASSES
MUST BE WORN.
(1) Disconnect battery negative cable.
(2) Loosen and remove drive belts, refer to Group
7, Engine Cooling.
(3) Using a R-134a refrigerant recovery machine,
remove the refrigerant from A/C system. If the compressor is being replaced.
(4) Disconnect compressor clutch wire lead.
(5) Remove refrigerant lines from compressor, if
necessary (Fig. 23).
Fig. 22 Blower Motor Resistor Block
1 – RESISTOR BLOCK
2 – ELECTRICAL CONNECTOR
(4) Remove/unsnap resistor block from vehicle.
INSTALLATION
For installation, reverse the above procedures.
BLOWER MOTOR WHEEL
The blower motor wheel is only serviced with the
blower motor. The wheel and the motor are balanced
as an assembly. If the blower motor wheel requires
replacement, the blower motor must also be replaced.
Refer to blower motor for replacement procedure.
COMPRESSOR
CAUTION: Add only new lubricant when system
requires additional lubricant. Do not use old
reclaimed lubricant.
Fig. 23 A/C Compressor Lines
1
2
3
4
5
–
–
–
–
–
CONDENSER LIQUID LINE
SUCTION LINE
COMPRESSOR MANIFOLD SCREWS
COMPRESSOR
DISCHARGE LINE
(6) If system is left open place plug/cap over open
lines.
(7) Remove compressor attaching bolts (Fig. 24).
HEATING AND AIR CONDITIONING
PL
24 - 23
REMOVAL AND INSTALLATION (Continued)
Fig. 24 A/C Compressor Mounting Bolts
1 – A/C COMPRESSOR
2 – MOUNTING BOLTS
3 – LOWER FRONT STRUT-TO-ENGINE BRACKET
(8) Remove compressor. If refrigerant lines were
not removed, lift compressor/clutch assembly and tie
it to a suitable component.
INSTALLATION
Fig. 25 Compressor Shaft Bolt and Clutch Plate
1 – COMPRESSOR SHAFT BOLT
2 – COMPRESSOR CLUTCH PLATE
CAUTION: Do not use screwdrivers between the
clutch plate assembly and pulley to remove front
plate as this may damage the front plate assembly.
For installation, reverse the above procedures.
• Tighten the compressor mounting bolts to 28
N·m (250 in lbs).
• Tighten the compressor lines to 12 N·m (108 in
lbs).
COMPRESSOR CLUTCH/COIL ASSEMBLY
Compressor assembly must be removed from
mounting. Although, refrigerant discharge is not necessary.
REMOVAL
(1) Remove the compressor shaft bolt (Fig. 25). A
band type oil filter removal tool can be placed around
the clutch plate to aid in bolt removal.
(2) Tap the clutch plate with a plastic hammer and
remove clutch plate and shim(s) (Fig. 26).
NOTE: Use care not to lose any of the shim(s).
Fig. 26 Clutch Plate and Shim(s)
1 – COMPRESSOR SHAFT
2 – CLUTCH PLATE
3 – CLUTCH PLATE SHIM
24 - 24
HEATING AND AIR CONDITIONING
PL
REMOVAL AND INSTALLATION (Continued)
(3) Remove pulley retaining snap ring with Snap
Ring Pliers, and slide pulley assembly off of compressor (Fig. 27).
Fig. 28 Clutch Coil Snap Ring
Fig. 27 Removing Pulley Snap Ring
1
2
3
4
–
–
–
–
SNAP RING PLIERS
CLUTCH COIL
COMPRESSOR
SNAP RING
1 – SNAP RING
(4) Remove coil wire bracket/ground clip screw and
wire harness.
(5) Remove snap ring retaining field coil onto compressor housing (Fig. 28). Slide field coil off of compressor housing.
(6) Examine frictional faces of the clutch pulley
and front plate for wear. The pulley and front plate
should be replaced if there is excessive wear or scoring. If the friction surfaces are oily, inspect the shaft
nose area of the compressor for oil and remove the
felt from the front cover. If the compressor felt is saturated with oil, the shaft seal is leaking and will
have to be replaced.
(7) Check bearing for roughness or excessive leakage of grease. Replace bearing as required.
INSTALLATION
(1) Align pin in back of field coil with hole in compressor end housing, and position field coil into place.
Make sure that lead wires are properly routed, and
fasten the coil wire bracket/ground retaining screw.
NOTE: A new snap ring must be used. The bevel
side of the snap ring must be outward.
(2) Install field coil retaining snap ring with Snap
Ring Pliers. Press snap ring to make sure it is properly seated in the groove.
CAUTION: If snap ring is not fully seated it will
vibrate out, resulting in a clutch failure and severe
damage to the front face of the compressor.
Do not mar the pulley frictional surface.
(3) Install pulley assembly to compressor. If necessary, tap gently with a block of wood on the friction
surface (Fig. 29).
(4) Install pulley assembly retaining snap ring
(bevel side outward) with Snap Ring Pliers. Press the
snap ring to make sure it is properly seated in the
groove.
(5) If the original front plate assembly and pulley
assembly are to be reused, the old shim(s) can be
used. If not, place a trial stack of shims, 2.54 mm
(0.10 in.) thick, on the shaft against the shoulder.
(6) Install front plate assembly onto shaft.
(7) If installing a new front plate and/or pulley
assembly, the gap between front plate and pulley face
must be checked. Use the following procedure:
(a) Attach a dial indicator to front plate so that
movement of the plate can be measured.
(b) With the dial indicator zeroed on the front
plate, energize the clutch and record the amount of
movement.
(c) The readings should be 0.35 to 0.65 mm
(0.014 to 0.026 in.). If proper reading is not
HEATING AND AIR CONDITIONING
PL
24 - 25
REMOVAL AND INSTALLATION (Continued)
INSTALLATION
To install, reverse the preceding operation. Check
the drain tube nipple on the heater-A/C housing for
any obstructions.
Fig. 30 Condensate Water Drain Tube – Typical
Fig. 29 Installing Pulley Assembly
1 – PULLEY ASSEMBLY
2 – WOOD BLOCK
obtained, add or subtract shims until desired reading is obtained.
(8) Install compressor shaft bolt. Tighten to 17.5 6
2 N·m (155 6 20 in. lbs.) torque.
NOTE: Shims may compress after tightening shaft
nut. Check air gap in four or more places to verify if
air gap is still correct. Spin pulley for final check.
1
2
3
4
–
–
–
–
DASH PANEL (UNDER HOOD RIGHT SIDE)
CLAMP
CONDENSATE DRAIN TUBE
NIPPLE-A/C HEATER HOUSING
CONDENSER
The condenser is located in front of the engine
radiator. It has no serviceable parts. If damaged or
leaking, the condenser assembly must be replaced.
WARNING: THE
REFRIGERANT
MUST
BE
REMOVED FROM THE SYSTEM BEFORE REMOVING THE CONDENSER.
CLUTCH BREAK-IN
After new clutch installation, cycle the A/C clutch
20 times (5 seconds on and 5 seconds off). During
this procedure, set the system to the A/C mode,
engine rpm at 1500 - 2000, and high blower speed.
This procedure (burnishing) will seat the opposing
friction surfaces and provide a higher clutch torque
capability.
CONDENSATION DRAIN TUBE
REMOVAL
(1) Raise vehicle.
(2) Locate rubber drain tube on right side of dash
panel (Fig. 30).
(3) Squeeze clamp and remove drain tube.
REMOVAL
(1) Using a R-134a refrigerant recovery machine,
remove the refrigerant from the A/C system.
(2) Remove battery support strut.
(3) Remove refrigerant lines from condenser (Fig.
31).
(4) Remove upper radiator mounts.
(5) Remove condenser to radiator mounting
screws.
(6) Tilt radiator back and remove condenser.
INSTALLATION
For installation, reverse the above procedures.
• Tighten the condenser refrigerant lines to 5 N·m
(45 in lbs).
24 - 26
HEATING AND AIR CONDITIONING
PL
REMOVAL AND INSTALLATION (Continued)
Fig. 31 Condenser Refrigerant Lines
1
2
3
4
–
–
–
–
LIQUID LINE
A/C LINE MOUNTING BOLTS
DISCHARGE LINE
CONDENSER
DISCHARGE LINE
WARNING: THE REFRIGERANT SYSTEM MUST BE
RECOVERED BEFORE SERVICING ANY PART OF
THE REFRIGERANT SYSTEM.
REMOVAL
(1) Using a R-134a refrigerant recovery machine,
remove the refrigerant from A/C system.
(2) From the top side of the vehicle, remove line at
compressor (Fig. 32).
(3) From the bottom side of the vehicle, remove
line at condenser.
INSTALLATION
For installation, reverse the above procedures.
EVAPORATOR
This vehicle uses an aluminum plate and fin style
evaporator. It is located in the Evaporator/Blower
module.
The unit housing must be removed from the vehicle before beginning with this procedure. Refer to
Unit Housing in this section for removal procedure.
Use this procedure if any or all of the following
items require service:
• Evaporator
• Air inlet duct
• Heater Core
• Heating and Air Conditioning
Fig. 32 Discharge Line
1
2
3
4
–
–
–
–
DISCHARGE LINE
A/C COMPRESSOR
HIGH PRESSURE CUT OUT SWITCH
SUCTION LINE
DISASSEMBLE
(1) Separate the foam seals at the evaporator line
connection, and the dash panel air distribution outlets (Fig. 33).
(2) Disconnect fin sensing probe from harness.
(3) Remove upper to lower case retaining clip and
screws.
(4) Separate the case halves (Fig. 34).
(5) Lift the evaporator out of the module (Fig. 35).
ASSEMBLE
To reassemble, reverse the above procedures.
EVAPORATOR PROBE
The evaporator probe can be removed without
removing the Unit Housing from the vehicle.
REMOVAL
(1) Disconnect probe wiring connector from behind
the glove box.
(2) Remove rubber grommet from evaporator/
blower module (Fig. 36).
(3) Note which of the three pilot holes the evaporator probe is located in.
(4) Pull probe out of evaporator fins.
INSTALLATION
(1) There are three pilot holes available for the
probe. The top hole is for service. If top hole was not
used by previous probe, install probe in top hole.
(2) If previous probe was removed from top hole,
use a small plastic stick of approximately 1/8 inch
HEATING AND AIR CONDITIONING
PL
24 - 27
REMOVAL AND INSTALLATION (Continued)
Fig. 35 Evaporator Removal - Typical
Fig. 33 Lower HVAC Housing
1
2
3
4
5
6
7
8
–
–
–
–
–
–
–
–
EVAPORATOR AND CONNECTION
FOAM SEALS
HEATER CORE AND TUBES
HVAC HOUSING LOWER CASE
HOUSING MOUNTING STUDS
HOUSING DRAIN
WIRING
BLOWER MOTOR AND WHEEL
1 – EVAPORATOR
2 – BLOWER WHEEL
(3) Insert new probe into hole between evaporator
fins.
(4) Reinstall rubber grommet into evaporator
probe access hole.
Fig. 36 Evaporator Probe Location - Typical
Fig. 34 Case Separation - Typical
1 – CASE HALVES
2 – EVAPORATOR
3 – BLOWER WHEEL
diameter, and make a new hole. Make the hole 1/4
inch above, or below the original hole in the evaporator core.
1 – EVAPORATOR PROBE WIRING CONNECTOR
2 – EVAPORATOR PROBE RUBBER GROMMET
3 – EVAPORATOR/BLOWER MODULE
EXPANSION VALVE
WARNING: THE REFRIGERATION SYSTEM MUST
BE COMPLETELY EMPTY BEFORE PROCEEDING
WITH THIS OPERATION.
24 - 28
HEATING AND AIR CONDITIONING
PL
REMOVAL AND INSTALLATION (Continued)
REMOVAL
(1) Remove the wire connector from the low pressure cut-off switch.
(2) Remove the center bolt of refrigerant line
plumbing sealing plate (Fig. 37).
(3) Carefully pull the refrigerant line-sealing plate
assembly from the expansion valve towards front of
vehicle. Do not scratch the expansion valve sealing
surfaces with pilot tubes.
(4) Cover the openings on A/C line-sealing plate
assembly to prevent contamination.
(5) Remove two screws securing the expansion
valve to the evaporator sealing plate.
(6) Carefully remove valve.
INSTALLATION
(1) Remove and replace the aluminum gasket on
the evaporator sealing plate.
(2) Carefully hold the expansion valve to the evaporator sealing plate so not to scratch the sealing surface. Install two screws and tighten to 11 6 3 N·m
(100 6 30 in. lbs.).
(3) Remove and replace the aluminum gasket on
the refrigerant line- sealing plate assembly.
(4) Carefully hold the refrigerant line-sealing plate
assembly to the expansion valve. Install bolt and
tighten to 23 6 3 N·m (200 6 30 in. lbs.).
(5) Connect wires to low pressure cut-off switch.
(6) Evacuate and recharge system.
(7) After expansion valve is installed, system is
charged, and leaks have been checked, repeat A/C
performance check.
Fig. 37 Expansion Valve - Typical
1
2
3
4
5
6
7
–
–
–
–
–
–
–
ALUMINUM N-GASKET
PLUMBING SEALING PLATE
LOW/DIFFERENTIAL PRESSURE CUT-OFF SWITCH
DASH PANEL
H-VALVE
EVAPORATOR SEALING PLATE
H-VALVE
1
2
3
4
–
–
–
–
COWL PANEL
HEATER HOSE AND CLAMPS
HEATER CORE TUBES
HEATER HOSE SUPPLY AND RETURN TUBES
HEATER CORE
Refer to HVAC Housing Disassembly and Assembly
in this section for heater core removal procedure.
HEATER HOSES
CAUTION: When removing hoses from heater core
inlet or outlet nipples DO NOT exert excess pressure. The heater core may become damaged and
leak engine coolant.
Fig. 38 Heater Hoses and Clamps
NOTE: Review Cooling System Precautions before
proceeding with this operation.
REMOVAL
(1) Drain engine cooling system. Refer to Group 7,
Cooling System.
(2) Using spring tension clamp pliers, remove
clamps at end of heater hose to be removed (Fig. 38).
(3) Carefully rotate hose back and forth while pulling away from connector nipple.
INSTALLATION
For installation, reverse the above procedures.
HEATING AND AIR CONDITIONING
PL
24 - 29
REMOVAL AND INSTALLATION (Continued)
HIGH PRESSURE CUT OUT SWITCH
WARNING: THE
REFRIGERANT
MUST
BE
REMOVED FROM THE SYSTEM BEFORE REMOVING THE HIGH PRESSURE CUT OUT SWITCH.
REMOVAL
(1) Disconnect wiring connector at the switch (Fig.
39).
(2) Remove internal snap ring.
(3) Pull switch out of compressor.
INSTALLATION
For installation, reverse the above procedures. Use
a new O-Ring Seal.
R-134a SERVICE EQUIPMENT OR VEHICLE A/C
SYSTEM SHOULD NOT BE PRESSURE TESTED OR
LEAK TESTED WITH COMPRESSED AIR. MIXTURE
OF AIR and R-134a CAN BE COMBUSTIBLE AT ELEVATED PRESSURES. THESE MIXTURES ARE
POTENTIALLY DANGEROUS AND MAY RESULT IN
FIRE OR EXPLOSION CAUSING INJURY OR PROPERTY DAMAGE.
REMOVAL
(1) Using a R-134a refrigerant recovery machine,
remove the refrigerant from A/C system.
(2) Rotate the high pressure relief valve counterclockwise and separate relief valve from the compressor (Fig. 39).
INSTALLATION
For installation, reverse the above procedures
using a new O-Ring Seal. Evacuate and charge the
refrigerant system.
LIQUID LINE
WARNING: THE REFRIGERATION SYSTEM MUST
BE COMPLETELY EMPTY BEFORE PROCEEDING
WITH THIS OPERATION.
REMOVAL
(1) Using a R-134a refrigerant recovery machine,
remove the refrigerant from A/C system.
(2) Disconnect liquid line at drier.
(3) Disconnect liquid line at condenser.
Fig. 39 High Pressure Cut Out Switch Location
1
2
3
4
–
–
–
–
DISCHARGE LINE
A/C COMPRESSOR
HIGH PRESSURE CUT OUT SWITCH
SUCTION LINE
HIGH PRESSURE RELIEF VALVE
WARNING: AVOID BREATHING A/C REFRIGERANT
AND LUBRICANT VAPOR OR MIST. EXPOSURE MAY
IRRITATE EYES, NOSE AND THROAT. USE ONLY
APPROVED SERVICE EQUIPMENT MEETING SAE
REQUIREMENTS TO DISCHARGE R-134a SYSTEM.
IF ACCIDENTAL SYSTEM DISCHARGE OCCURS,
VENTILATE WORK AREA BEFORE RESUMING SERVICE.
INSTALLATION
For installation, reverse the above procedures.
LOW PRESSURE CUT OFF SWITCH
WARNING: THE REFRIGERATION SYSTEM MUST
BE COMPLETELY RECOVERED BEFORE PROCEEDING WITH THIS OPERATION. REFER TO
REFRIGERANT RECOVERY SECTION.
REMOVAL
(1) Disconnect the wire connector at the cut off
switch.
(2) Using a sender unit removal socket, remove the
switch from the expansion valve (Fig. 40).
24 - 30
HEATING AND AIR CONDITIONING
PL
REMOVAL AND INSTALLATION (Continued)
INSTALLATION
NOTE: Verify the O-ring condition on the replacement switch.
For installation, reverse the above procedures.
Evacuate and charge the system.
Fig. 41 Instrument Panel Center Bezel & Knobs
1
2
3
4
5
–
–
–
–
–
1
2
3
4
–
–
–
–
INSTRUMENT PANEL CENTER AIR DUCT
OUTSIDE AIR/RECIRC CONTROL KNOB
MODE CONTROL KNOB
BLOWER SPEED KNOB
TEMPERATURE CONTROL KNOB
Fig. 40 Expansion Valve and Low Pressure Cut-Off
Switch
1
2
3
4
–
–
–
–
EXPANSION VALVE
LOW PRESSURE CUTOFF SWITCH
LIQUID LINE
SUCTION LINE
MODE CONTROL CABLE
The Mode Control Cable can be removed and
installed without having to remove the instrument
panel from the vehicle.
REMOVAL
(1) Remove instrument panel center stack bezel
(Fig. 41).
(2) Remove center air duct (Fig. 42).
(3) Remove heater-A/C control head and disconnect
cable (Fig. 43).
(4) Disconnect cable at heater unit.
(5) Remove cable from vehicle.
INSTALLATION
For installation, reverse the above procedures,
adjust cable and test. Refer to Mode Control Cable
Adjustment at the end of this section.
Fig. 42 HVAC Center Air Duct & Control Head
CENTER AIR DUCT
INSTRUMENT PANEL
HVAC CONTROL HEAD
ATTACHING SCREWS
HEATING AND AIR CONDITIONING
PL
24 - 31
REMOVAL AND INSTALLATION (Continued)
Fig. 43 HVAC Control Head Cables
1
2
3
4
–
–
–
–
HVAC CONTROL HEAD
ELECTRICAL CONNECTOR
CONTROL CABLES
VACUUM HARNESS
RECIRCULATION DOOR ACTUATOR
The recirculation door actuator is a vacuum controlled actuator used to control movement of the
recirculation door in air conditioned equipped vehicles.
The instrument panel must be removed from the
vehicle to gain access to the recirculation door actuator.
Fig. 44 Recirculation Door Actuator and Linkage
1
2
3
4
5
6
–
–
–
–
–
–
OUTSIDE AIR/RECIRC DOOR HOUSING
VACUUM ACTUATOR LINKAGE
FOAM SEAL
RECIRC DOOR VACUUM ACTUATOR
DOOR LEVER
DOOR LEVER
REMOVAL
(1) Using a R-134a refrigerant recovery machine,
remove the refrigerant from A/C system.
(2) Remove retaining bolt at expansion valve (Fig.
45).
REMOVAL
(1) Remove instrument panel from vehicle. Refer
to Group 8E, Instrument Panel And Systems for
removal procedures.
(2) Disconnect vacuum line from actuator.
(3) Disconnect actuator from recirculation door
link (Fig. 44).
(4) Release tension on latch, and slide recirculation door actuator off housing.
INSTALLATION
For installation, reverse the above procedures.
SUCTION LINE
WARNING: THE REFRIGERANT MUST BE RECOVERED BEFORE SERVICING ANY PART OF THE
REFRIGERANT SYSTEMS.
Fig. 45 Expansion Valve Center Bolt
1
2
3
4
–
–
–
–
EXPANSION VALVE
LOW PRESSURE CUTOFF SWITCH
LIQUID LINE
SUCTION LINE
24 - 32
HEATING AND AIR CONDITIONING
PL
REMOVAL AND INSTALLATION (Continued)
(3) Remove line at expansion valve.
(4) Remove line at compressor (Fig. 46).
Fig. 47 HVAC Housing Cables
1
2
3
4
5
6
–
–
–
–
–
–
VACUUM HARNESS
DOOR CAM
HVAC UPPER HOUSING
HVAC CONTROL HEADS CABLES
MODE DOOR LEVERS
DEFROSTER DUCT OUTLET
Fig. 46 A/C Compressor Suction Line
1 – FILTER DRIER
2 – SERVICE PORTS
3 – FILTER DRIER MOUNTING GROMMET
4 – EVAPORATOR LINE BLOCK
5 – EXPANSION VALVE
6 – LOW PRESSURE CUT OUT SWITCH CONNECTOR
7 – HVAC HOUSING DRAIN OUTLET
8 – CONDENSATE DRAIN TUBE
9 – EXPANSION VALVE SCREWS
10 – CONDENSER LIQUID LINE
11 – COMPRESSOR SUCTION LINE
INSTALLATION
For installation, reverse the above procedures.
TEMPERATURE CONTROL CABLE
The Control Cable can be removed and installed
without having to remove the instrument panel from
the vehicle.
REMOVAL
(1) Remove instrument panel center stack bezel
(Fig. 41).
(2) Remove heater-A/C control head (Fig. 42).
(3) Remove center air duct.
(4) Disconnect cable at control panel. Remove control from instrument panel.
(5) Disconnect cable at heater unit (Fig. 47).
(6) Remove cable from vehicle.
INSTALLATION
For installation, reverse the above procedures,
adjust cable and test. See Temperature Control Cable
Adjustment in this section.
UNIT HOUSING
The instrument panel must be removed in order to
remove the Unit Housing. Refer to group 8E Instrument Panel and Systems for detailed procedure.
WARNING: THE R-134a REFRIGERANT SYSTEM
MUST BE RECOVERED BEFORE SERVICING ANY
PART OF THE REFRIGERANT SYSTEM.
REMOVAL
(1) Using a refrigerant recovery machine, remove
the refrigerant from the A/C system, if equipped.
(2) Remove instrument panel from vehicle. Refer
to group 8E Instrument Panel and Systems for
detailed procedure.
(3) Drain cooling system and remove heater hoses
at the dash panel. Place plugs in the heater core outlets to prevent coolant spillage during unit housing
removal.
(4) Unfasten coolant recovery container and set
aside.
(5) Remove suction line at expansion valve. Cap
open refrigerant lines to prevent moisture and/or dirt
from entering.
HEATING AND AIR CONDITIONING
PL
24 - 33
REMOVAL AND INSTALLATION (Continued)
(6) Remove expansion valve from evaporator, and
cap fittings.
(7) Remove rubber drain tube extension from condensation drain tube.
(8) Disconnect the vacuum harness at the power
brake booster (Fig. 48).
(10) Remove three retaining nuts located in the
engine compartment, on the dash panel (Fig. 50).
Fig. 50 Dash Panel Retaining Studs
Fig. 48 HVAC Vacuum Harness
1 – BRAKE POWER BOOSTER
2 – A/C VACUUM CHECK VALVE
3 – VACUUM HARNESS
1
2
3
4
5
6
–
–
–
–
–
–
BLOWER RESISTOR
EXPANSION VALVE
DRAIN TUBE
DASH PANEL
HEATER HOSES
RETAINING STUDS
(11) Remove the right side retaining screw (Fig.
51).
(9) Unsnap and remove the defroster duct (Fig.
49).
Fig. 51 Housing Screws
1
2
3
4
Fig. 49 HVAC Housing Defroster Duct
1
2
3
4
–
–
–
–
DEFROSTER DUCT
BODY
ELECTRICAL CONNECTOR
HVAC HOUSING
–
–
–
–
RIGHT SIDE RETAINING SCREW
EVAPORATOR PROBE GROMMET
SCREW BOSSES
DASH PANEL STUD AND NUT
(12) Remove remaining nut located on dash panel
stud.
(13) Disconnect the wiring connectors.
(14) Remove assembly from the vehicle.
24 - 34
HEATING AND AIR CONDITIONING
PL
REMOVAL AND INSTALLATION (Continued)
INSTALLATION
For installation, reverse the above procedures.
DISASSEMBLY AND ASSEMBLY
HEATER-A/C HOUSING
Use this procedure if any or all of the following
items require service:
• Heater core
• Evaporator
• HVAC housing
The HVAC housing must be removed from the
vehicle before beginning with this procedure. Refer to
Unit Housing in this section for removal procedure.
DISASSEMBLY
(1) Separate the air distribution outlet foam seals
at the case parting line (Fig. 52).
Fig. 53 HVAC Housing Evaporator Connection and
Heater Core Tube Seals
1
2
3
4
5
6
7
8
–
–
–
–
–
–
–
–
EVAPORATOR AND CONNECTION
FOAM SEALS
HEATER CORE AND TUBES
HVAC HOUSING LOWER CASE
HOUSING MOUNTING STUDS
HOUSING DRAIN
WIRING
BLOWER MOTOR AND WHEEL
ASSEMBLY
To reassemble, reverse the above procedures.
ADJUSTMENTS
MODE CONTROL CABLE
Fig. 52 HVAC Housing Air Distribution Foam Seals
1
2
3
4
5
6
7
–
–
–
–
–
–
–
AIR DISTRIBUTION
RECIRCULATION DOOR VACUUM ACTUATOR
AIR INLET
BLOWER MOTOR
EVAPORATOR PROBE CONNECTOR
CONTROL CABLES
VACUUM HARNESS
(2) Remove the evaporator lines foam seal, and
heater core tubes foam seal from the unit (Fig. 53).
(3) Remove the retaining clips and screws that
hold the upper and lower housings together.
(4) Separate the two halves of the housing.
(5) Lift the heater core/evaporator out of the case.
(1) Engage cable to actuator arm lever on mode
door and attach to housing (Fig. 47).
(2) Attach other end of cable to instrument panel
control (Fig. 43).
(3) Turn the mode knob completely counterclockwise.
(4) While holding the knob in the counterclockwise
position, pull on the gray casing of the mode cable.
This will take up any free play in the cable and index
the mode door to the mode knob.
(5) Then snap the cable hold down clip into position.
TEMPERATURE CONTROL CABLE
(1) Engage cable to actuator arm on temperature
door and attach to housing (Fig. 47).
(2) Attach other end of cable to instrument panel
control (Fig. 43).
(3) Turn the temperature knob completely counterclockwise.
PL
HEATING AND AIR CONDITIONING
24 - 35
ADJUSTMENTS (Continued)
(4) While holding the knob in the counterclockwise
position, pull on the gray casing of the temperature
cable. This will take up any free play in the cable
and index the temperature door to the temperature
knob.
(5) Then snap the cable hold down clip into position.
(6) Remount control.
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