My A/C was cutting out about 2 weeks ago on my 2000 2.8 A4, the blower was fine but the air wasn't being cooled. I took it in to my local shop who said the system was fine and ran a leak test on it (which showed no leaks), recharged the system and it worked great until today. If it's working it's lost most of its intensity, does that sound like a leak to you guys, or is there something else I should be looking at?

 

im in the same situation also

 

The compressor has a safety feature that protects the rest of the system if it is over charged which will cause shotty cooling. Sometimes on, sometimes off. If you can get ahold of vag com, you can scan the HVAC control module for faults. Otherwise its mostly guess work with a multimeter.

 

The outside temp sensor sometimes displays incorrect temps, like -10 degrees, which tells the A/C to shut down as if it were too cold out. Mine did this the other day and I just happened to see the reading on the instrument cluster. I still don't know why my sensor was malfunctioning.

 

Good point, of coursethats only if AUTO is seclected on the unit. If you get cold air without AUTO selected then that's probably the problem.

 

My AC doesn't work in either mode. I hear that no matter what mode you use, if the outside temp is below freezing or your car thinks it is below freezing because of a faulty outside temp sensor, the AC will NOT come on, this is to prevent damage to the system as there is no reason to cool air that is below the output temp.