dr bob

What does your meter read for battery voltage (jump-start terminal voltage is OK) when you are doing this test?

11.3 is low, considering the car should be at ~14 volts with engine running. At the same time, 11.3 should be enough to pull in the compressor clutch.


Going back to a previous post, if you apply jump-start terminal voltage to the freez switch terminals with the wiring still connected, does the clutch pull in?

JG928S4

no, clutch does not pull in, when car is running I have 14 on the meter, I think I have been running the ac switch/fans too much w/out car running lately.

dr bob

OK--

Did you try the jumper from the jump-start post to the freeze switch yet?


The circuit starts at the relay in the control head, through a harness connector T29, to the freeze switch. From there it passes through the central electrics panel at H15 (for MY 1989 anyway), and branches to a few places. One is the surge suppressor in position XI, another is out of the CE panel at M12. From there it goes to the pressure switch. From there it passes through the 14-pin connector under the jump-start terminal. From there it goes to the harness across the front of the engine. From there it connects to the clutch coil positive wire by the engine oil dipstick and the right side (pass side on US cars) timing belt cover. Current flows through the coil, and drains to engine ground through a short pigtail that's usually grounded to the compressor housing.

JG928S4

Ran a 16 gauge wire from the start post to both plugs on the freeze switch, did not hear a thing. Ignition and A/C switch off, read 12.5 volts on both plugs of freeze switch.

j.kenzie@sbcglobal.net

Maybe a bad wire to compressor. There is a connector in front of PS cam cover which leads to compressor. Could have been pulled loose?

JG928S4

How do I just jump the compressor so I can feel cold air and eliminate it as a problem?

j.kenzie@sbcglobal.net

You are looking for the wire going to the compressor clutch. Trace up from top of compressor towrd PS cam cover. 12V from jump post to this wire should give a good click as clutch engages. If it does then I suspect the factory wiring is bad. If no click with 12V direct, then suspect the clutch itself.
Good luck.

JG928S4

Having trouble finding the compressor 12 v line, removed ait intake tubing, 12v post cover, got under the car w/the flashlight, felt around the compressor and in betwen the air pump, I found a black line w/ a black rectangular box on it in between the wire harness and above the air pump, but nothing tracing down to the compressor. Does 12V hook to the front or rear of the compressor?

j.kenzie@sbcglobal.net

That rectangular box is a coupling leading to the clutch. You can tap in just below it. It is very hard to find these wires.

Tampa 928s

Wire is on top of the compressor about 12 inches long and mates to a plug off of the harness. Look at your tension belt sender wire should be near that or behind the cap. I believe it switches ground not 12V.

j.kenzie@sbcglobal.net

Pretty sure it's 12V

JG928S4

Couldn't find the wire, so just gave it a shot and did the Radio Shack Relay switch change over. Got Air Conditioning compressor to engage, and cold air to blow, but not Icy cold, but a lot better than w/none with it being over 105 here every day. I do notice that when I switch the vent switch lever I always have air coming thorugh the center vent, I guess I need to tackle that next, will start researching the vacuum section.

Thanks to all whom had patience with me the last few days, this user group definetly tops the 911 and Audi groups for assitance, or is it just that I have a lot more to fix on this car??