When i'm in neutral and my a/c is on, i hear a clicking noise in the engine bay that engages every 5-10 seconds. When the clicking sound happens my idle drops to a little lower than 500rpm and the car shakes like hell. It reminds me of when you leave your car in gear by accident sometimes and brake w/o hitting the clutch. Also, when idle speed drops, the electrical systems dim.

However, when i'm in neutral w/o a/c the car is fine and idling at 725rpm.....my haynes manual says the car should idle between 650-750rpm. A friend said i should just adjust the idle speed to go higher but won't that mess up my engine?