Not sure how the AC Compressor works, but I have noticed when it seems to kick on, it stalls my engine a little bit. Not sure if I'm saying that right, but when I have the air off my car normally idles at about 800 rpm, when I turn the air on it idles at 1000 rpm, then when the compressor turns on it drops to 500 rpm, then jolts back up to 1000 rpm. When it drops the engine shakes. I'm not sure if I just need to the change the AC Compressor or if it could be another problem. Let me know if you know anything.