Hello everyone,

I have a college exchange student staying at my house. He arrived in a 1995 Audi quattro 90. His AC does not work. I am hoping to repair it. I have experience with auto repair on Chryslers, Infiniti's and Nissans. I also have experience and equipment for home Air Conditioning This Audi seems a bit different to me and documentation is hard to find. I have searched the web and this site and have done the following.

1. Observed that when the car is started the AC clutch operates for 3 sec.
2. Swapped a couple of relays and verified that the AC relay is functioning and it does open and close when inserted and removed.
3. Verified that the high speed fan setting operates.
4. Jumped the pressure switch with no change in operation
5. Depressed the high side pressure port, there is pressure/refrigerant
(134a according to the label)
6. Note that in the fuse/relay panel under the hood, in front of the AC relay there is a space labeled low speed fan relay. This space is empty. There are other empty relay sockets but they are covered with a label that says not used.
7. Note that the air bag light is on.
8. Note that when the car is started, sometimes there is a flashing red thermometer that appears and then goes away.

Any suggestions on what to try next would be appreciated.

Pete S

 

Add some coolant and the red thermometer will go away.

 

Where is the low preesure port so refigerant can be added?

 

On this vehicle, there is a port located on the evaporater in front of the radiator, towards the left side i believe. There is an upper and a lower, I was told be a mechanic that they usually prefer to use the lower, but I have not been able to locate it yet. The one on the evaporator is the upper and should work fine.