My air conditioning stopped working about 3 months ago in my 2003 audi 1.8t. I work at a repair shop and we tried putting 134 (free on) in the other day but still nothing. It calls for 1.1 pounds but It hasn't helped it. It's hard to tell if the compressor is even running because the clutch isn't external. It's getting power to the compressor but i don't know if its running. I don't hear it like I do most compressors but I never really heard it when it did work. Any info on how to check the compressor or any other things I can look for??? That would be great....the compressor is big money and our next step was to see if the dryer needed to be replaced. And I was told that the ac compressor should be working if its taking free on in so thats leads me to believe its something else...any tips? thanks.