aeronautica86

Ok, this is for an '86 951 by the way.

I bought the car day before yesterday and the only issue that needs fixing asap is the a/c as I live in Texas and its freakin hot. The control unit seems to work fine - the *****, buttons etc function but no cold air. I'm pretty sure its not the heater clip because when that happened with my old n/a it would blow hot air on the highest setting regardless of position of the fan ****.

The previous owner says it has something to do with the cabin temperature sensor (the thing beside the cigarette lighter), could this be the problem? If so what do I need to replace? I haven't check the system to see if it has refrigerant, but there are no leaks so I think everything in the engine bay is working fine, and I believe the problem to be something in the cabin, but then again, I am no a/c expert.

Any ideas? Thanks in advance!

joes

I could be wrong but I believe that if the cold **** is turned all the way cold and you push the AC button the comperssor should run.
1. The low pressure switch is broke or there is no freon in the system ( jump it out )
2. the compressor relay is bad
3. The control unit/ AC switch is bad
4. wiring to to the compressor is bad or burned out clutch.

I would jump out the low pressure switch, and turn it on. If it doesn't have 12 volts at the compressor, look for control power at the compressor relay. If there is no control power at the relay replace the control unit.

testarossa_td

Possible on the cabin air temp...but those rarely go bad.
Try and turn the air on and see if you see the compressor engage.
Then try the LPR switch jump.
From there it could be several differnt things, or a little from column A and a little from Column B

The AC control unit can have multiple issues alone.

Clark W

Could be just a coincidence, but I'm in the same boat. My temperature sensor in the dash has gone bad (is producing an audible whirring at this point) and the A/C has stopped working. Compressor is engaging when I switch the system on.

good luck, -c

dme

I think it is very doubtful that the temp sensor is the culprit. These things are simply little thermisters. Not much to go wrong there. It would more likely be the control unit or as stated above the low pressure cutout on the compressor. It is common to have a whiring sound from the internal sensor area as there is a little fan in there to move the air. It probably needs cleaning.

hosrom_951

Pge 87-63 in the manual states that a faulty interior sensor would create a sugglish regulation and system overheating.......

aeronautica86

Update: I really haven't had time or a place to do much checking on the system as I'm kinda in limbo between my mom and my dads place for the summer, but I did mess with it a tiny bit before work. When I push the a/c button I can hear some type of clicking sound, and the button will not stay depressed. If I hold the a/c button down while the blower is going the intensity of the blower increases slightly, but still no cold air (not hot air though). Maybe just a faulty a/c switch and low/old refrigerant? Could that be the problem? Can the snowflake switch itself be replaced without replacing the entire a/c control unit?

Also, I'm pretty sure its not the cabin temp sensor as the previous owner seemed to believe, but I mentioned that because I assume his (fairly knowledgable) mechanic told him, but I suppose that was wrong.