New owner of a 2000 1.8t A4 Quattro and new to Audis also; The AC works great until i come to a stop and am idling, then it just blows hot air until i get going again. I did some searching and it seems like it could be a few different things like possibly the auxilary fan? Any suggestions on what to check? Thanks in advance.

 

sounds like a bad compressor...?

 

I hope that's not the case but thanks

 

Unfortuanly I do not know enough about ac to help, but do to happen to live in virginia? I saw a car identical to yours for the first time is warrenton earlier

 

No, i'm in Ga

 

Aux. fan is my guess. I just had the exact same problem and it was an inoperable auxillary fan. It's easy to test. Open the hood with the AC on high and it will be running or not. If running you have other problems. If not it is the fan or one of the controllers.

Mine was the temp sensor at the lower driver's side of the radiator. It's an easy fix.

Start by trying to goose the fan with 12 volts and see if it spins. Check the 40 amp fuse under the dash panel to make sure it is good. You need to remove the lower portion of the dash wich is hard the first time then gets real easy.

If the fuse is good then you need to see if the water temp sensor is good. STFA for test procedures and I'll see if I can find the info I used to test mine and post here. Good luck

A new fan is $70 from ECS Tuning and the switch is about $25 so no big expense.

You will need to go to service position to change either one so fun times ahead.

 

Check out the 3rd photo for dash removal.

AudiWorld Tech Articles

Read this thread too

A/C Condenser Fan Not Working! - AudiWorld Forums

This is the article refered to in post #14

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I hope this helps.

It's not going to be the compressor I hope. Good luck.

Don't worry about the FCM, Fan Control Module, until you have exhausted the other, cheaper, possibilities.

 

Awesome info- thanks for the help; I checked w the ac on high and the aux fan does nothing- this is a good start, thanks again!

 

Let me know if you need more assistance. Glad to help.

Actually my fan was operational with a 12v goose but I replaced it anyway since it sounded like it was about to die.

 

If the fan doesn't run, pull the plug on the thermal switch on the lower radiator hose. Then bridge as shown here.



If fan doesn't run, its down to the fan or the wiring from that switch to the fan. If that does run the fan, start looking here: