A/C not working
 

Hey Guys,
I have been picking away at the all of the "little things" on my car lately and am trying to fix my air-conditioning.

It had been working and then the heater clip broke. I fixed the heater clip and then shortly after, the a/c compressor stopped coming on. I transplanted a HVAC controller from another 944 to see if it was just the dash switch, but nada. I checked all fuses and all are fine.

If I press the a/c button, the fans come on and it acts like it wants to work, but no compressor. So finally I put power right on the compressor and it came on and cooled. What is keeping the compressor from getting power?

Thanks,
Brad

Low-pressure safety switch. You're low on refrigerant. Do NOT run the system, you will run the risk of damaging it.

Just take it out. :)

You could have a bad clutch on your compressor.

Well, like I said, it works if a put power directly on the clutch, it just isn's getting power for some reason.

You are correct and the reason it's not getting power is you are low on refrigerant as Aaron stated. Refill the a/c system and the problem goes away. As Aaron also said, low refrigerant = low oil....low oil = lockup of compressor.

Okay, I forgot to mention that I plugged my pressure gauge into the system to check the pressure; I understand that this can cause damage. The pressure checked out fine, even when the compressor was running. Something else is keeping the compressor from getting power.

Pull the wires on the low pressure switch and see if you have power on one side. Could be a bad switch there.

+1

Alright, I just looked on Clarks-Garage for information... this is the one thing that he doesn't have much info on!!! So where exactly is the low pressure switch located? How can I test it? I also read something about a relay behind my glove-box... should I check here?
Multas Gratias!!
Brad

It is almost always the low pressure switch, check that first. The switch is #11 in the linked diagram.

http://www.pelicanparts.com/944/944_parts/944_83-85/Pic103.jpg

Thank you so much! I am headed home this Wednesday to begin work on it... I hate to have the a/c down for too much longer for fear of more problems.
Thanks!
Brad

You say the pressure checked out fine, just curious what the readings were with the compressor on/off?

Check for 12V on one side of the low pressure switch, then if you have it check for 12V on the other side. If you have proper pressure and 12V on one side, then build a small jumper wire to connect the two sides (or in the case of mine since the terminals are bare, just touch them together) and check if the compressor kicks on.

The low pressure switch is located either on or immediately beside the receiver/dryer behind the driver's side headlight. It has 2 wires going to it with terminals on them (there is another switch there that is hard wired, that is not the low pressure switch).