Last year I took my 2004 s4 to a local shop because my ac was blowing out warm air. they said that they had to charge the system and I may have a small leak and have to charge it once a year or find the leak. Well this year my ac started blowing warm air again, so I checked the charge and my low side is reading high pressure and it does not seem like my compressor is not running.Anyone have any advice?? I checked my fuses along the drivers side door and everything looks good no blown fuses.

Anything would help me out. I find it hard to believe that I would need to replace my compressor at 48,000 miles

Thanks