engine revs up and down when idling, only when A/C is on on 2002 Chevrolet Cavalier

When I'm idling, the car sometimes revs between 500-1000 rpm, over and over again until i start moving. It generally only happens when the A/C is on....

by in Los Angeles, CA on October 04, 2010
2 answers
ANSWER by on October 05, 2010
this may be normal as the idle will kick up when the ac compressor cycles on and off.
ANSWER by on November 18, 2010
You could have a vacuum leak or the fans are not working. The fuse box in the engine compartment left fender there is a relay for the A/C and one for the heater fan. The one for the A/C controls the fans. Switch the A/C and blower motor relays, turn on A/C, If the fans come on the relay will cost about $10 .