Some Tips from Don Thibault

January/February 1987
1. A 142/44/45 temp. sender can be substituted for the ' temp. sender on a '70-73 E/ES with the addition
of a 10 ohm resister, just in front of the sender.
2. A very effective (and inexpensive) kill switch can be added to the E/ES by just disconnecting the fuel
pump wire at the fuse box and adding a switch; the car will start,. then quickly sputter and stall!
3. If your speedometer cable doesn't turn but is not broken, check the shear pin inside the right angle
drive. The pin is actually a short length (about 1" long) of squared cable, still available from Volvo, I
Call or write any time. Technical advice; glad to help, if I can.
July/August 1987
Keeping cooler: two ways to increase the effectiveness of your air conditioner. Block off the air extraction
vents ('70-73 models) in the back seat area. Just remove the plastic grills and cover the openings with
black tape or plug them up with a scrap of cloth. Then replace the covers. Adding a cooling fan behind the
grille also helps. (This will keep your car from overheating when you're stuck in a traffic jam on a hot
day, too.) Any small cooling fan that fits will do nicely. I got mine from a Subaru - cost $20 at a salvage
yard. Just be sure to hook up the polarity correctly, so the fan blows into the radiator, not away from it.
On '70-73 models, the charcoal canister must be removed to install the fan. Don't worry, it's probably
useless anyway, the bottom having long ago rusted out.
I've noticed some interest in installing an air conditioning unit in the 1800, and since I installed one from
scratch on my '71E two years ago, I'll describe the procedure. It's not as difficult as one would think; the
Fridge King unit with York compressor is essentially a hang-on unit, even when factory installed.
You can start anywhere, but for this article I'll start from the front and work back. First, remove the hood
and grille. Mount the condenser in the grille compartment by hanging it in front of the radiator, as low as
possible so the hood won't hit it when it opens.
Cut a 2"x2" square out of the radiator support (or 2 individual holes), and run the hoses through it to the
left of the radiator. (The overflow bottle for the radiator will have to be repositioned slightly.) Let me say
here that you must use a rubber grommet everywhere the hoses go thru metal to prevent chaffing. There is
a good deal of vibration when the unit is running, and no hoses should be up against anything, or they will
chafe through in a surprisingly short time.
Mount the compressor on the left side of the engine block. (On the B-20E the mounting holes are already
in the block and tapped; run a tap thru anyway to clean them out.) Now mount the idler pulley on the
block. On my car the hole was drilled but not tapped.
Next, remove the alternator/water pump belt and the crank pulley, and replace it with the double pulley
necessary for the AC compressor. Replace the alt/wtrpump belt and add the compressor belt, setting the
tension with the idler pulley.
Working inside the car, drill two holes large enough to accommodate the freon hoses in the firewall, just
above the accelerator pedal. These holes will determine the location of the receiver/dryer.
Back in the engine compartment, mount the receiver/dryer on the firewall. Experts recommend it be
replaced each time the system is exposed to air, as the desiccant inside can become saturated with
moisture and become ineffective; however, I did not replace it, and the system works fine.
You should hook up the Freon hoses as you go. With the exception of the evaporator inside the passenger
compartment, all the hose connections are made with hose clamps. It may be a good idea to double clamp
them as I did, and be sure to sock them up tight.
Back inside the car, mount the evaporator under the dash on the passenger side. As I recall, it shares at
least one bolt with the fuel injection computer. Next, mount the small control panel under the dash with
the existing heater/defroster control right in the center. You will find a long temperature probe wire which
runs inside the control panel duct; place it inside the fins of the evaporator. The other end of the probe
wire is connected to the temperature switch on the control panel. This switch turns the compressor clutch
on and off to maintain the evaporator at aprox. 35°F. The evaporator would quickly ice up at a lower
Drill a hole in the floor large enough to accommodate the drain hose, which lets out the condensed
moisture removed from the air when the system is running.
Electrical connections are simple enough. Connect the four wires as follows: one power wire from the
fuse box to the control panel, one ground wire, one wire from the control panel to the compressor clutch,
and one wire from the control panel to the evaporator fan.
Your air conditioning unit is now installed and ready to be charged. I won't go into the charging of the
system except to say, follow the directions on the charging kit carefully. I charged mine myself and it
came out fine, but you can have the system professionally evacuated and charged at an AC shop.
The installation of an AC unit on the '61-'69 1800 is essentially the same. These are some of the
differences: The receiver/dryer is mounted near the radiator; the compressor requires a different mounting
bracket; the control panel, evaporator, and fan are all one unit which mounts under the dash in place of the
heater/ defroster control. That control must be repositioned to the right.
If you buy a used AC unit, be sure it's complete: all hoses, grommets, double crank pulley, etc.
May/June 1988
Upper Control Arm Bushings
Every fuel Injected 1800 I get in has bad upper control arm bushings on the passenger side due to the heat
of the exhaust manifold. To check yours, jack up the front end slightly, then grab the top of the tire and
pull towards you. You may be surprised to see it move an inch or more. While the bushings are a little
tough to get at, they are inexpensive and easy to replace.
September/October 1988
Here are a couple of problems and fixes I've run across on 1800s. The first was a 73 ES I picked up which
was running fine. When I went to move it after it had sat awhile in the driveway, it idled rough and kept
fouling plugs. After a quick check of the ignition system, I moved on to the fuel injection system. First
check was fuel pressure. To check fuel pressure, disconnect fuel line at the cold start injector and hook up
a pressure gauge (an old oil pressure gauge will do nicely). Next, disconnect terminal 87 of the pump
relay and, using a jumper, temporarily connect it to the positive side of the battery. This will run the pump
and give you a reading on the gauge. In this case the gauge only went up to 60 lbs. and that's what the
gauge read. Correct pressure would be 28 to 32 lbs. The regulator is adjustable, but in this case it was junk
and needed to be replaced. Problem solved!
Next problem was a 67S. The brakes would lock up, but when allowed to sit, they would free themselves
up. Opening up the bleeders on the front calipers would free them up also. The problem lies with the
brake booster not releasing the pressure usually attributed to a blocked air filter on the booster. But in this
case, the filter was clear and the problem was internal. The fix was simple though. I just removed the
small air filter and poured a small quantity of brake fluid in the air hole. Have someone else pump the
brakes while you tap gently on the housing and presto! the booster is freed up. Do not use any kind of oil
such as WD40, because it will distort the seals and ruin them.
May/June 1989
This article will be about usually neglected item on the 1800 differential.
The only time most owners look at it is when it starts making strange noises, and then it usually too late to
prevent major repairs.
A really good idea is to change the oil, tomorrow would be a good time. Easy to do, there are two plugs,
one high, one low. Drain the low fill the high with 80/90 wt. gear oil The number one cause of failure in a
differetial is lack of lubrication; be sure the oil level is up to the high mark at all times.
If the front pinion seal is leaking and you don't want to replace it, try cleaning all the dirt away from it.
This may slow the leak down a bit, since the dirt has the effect of wicking the oil out.
The 1800 (at least the 70-73 models) were available with an optional Spicer/Thornton limited slip
differential, manufactured by Dar Corp., Fort Wayne, IN. I suppose it's possible some owners may have a
limited slip differential and not know it. Once the cover is removed, or can tell by looking at it. On the
limited slip one cannot see the smaller bevel gears; all that can be seen is the large ring gear. If you have a
limited slip differential, you must add special lubricant with the oil for the clutches It is available through
Volvo or auto part stores.
I have a 12-page installation/maintenance manual that came with the limited slip on my '71E. I would be
glad to send out a copy t anyone for $2.00 to cover the copying costs Please send a SASE and I'11 get it
out to you.
November/December 1989
I'm sure all of you have noticed that the electrical terminals and relays on your 1800E/ES are all
numbered. This numbering system is not random and, by identifying the terminal number, one can
determine the function of the system. This holds true of other cars as well. Here are a few things I've
Terminal #15 - supply current only when ignition is on.
Terminal #30 - supply current from battery (always on).
Terminal #31 - is ground between a switch and an electrical component.
Terminal #85 - ground to chassis.
Terminal #50 - supply current only when ignition switch is in start position.
A letter suffix is used if two circuits have similar functions.
DON THIBAULT, 372 Route 6A,
E. Sandwich, MA 02537, (508) 888-9715
FAX 508-833-9026