I am new on this site and didn't know where to post my question, I also posted in the 3rd gen section.
When I turn my A/C on and I am at a traffic light, the rpm will go up and down between 500 and 1000 rpm and I will have warm air for a while, when the rpm's stabilize and return back to the normal 500 rpm range, I begin to get cold air again.

2002 Cavalier