1999 Pontiac Grand Prix - Wiper issue

My wipers have developed a problem. Sometimes, after use they don’t return to park, sometimes they do. They will begin operating without any switch action, making one or multiple cycles, sometimes stopping in the parked position, sometimes not. They cycle intermittently whether in park position or not. The wipers perform as commanded by the switch controls. I have connected ground from battery directly to wiper motor. Doesn’t resolve problem.

I’d say you have a bad “park” switch inside the wiper motor assembly.Replacing the wiper motor should fix the problem.


That can be caused by a defective wiper motor pulse board.