When it’s very hot or humid outside, my wipers don’t work as they should. When I start the car, the wipers start going even though the switch is in the off position. They cycle through a few times and stop in random positions. The speed changes register just fine. Does anyone know what the cause is for this?

 

I have had the same issue. And sometimes they only work when I have the cabin blower running. Its intermittent and does not happen often enough to bother me.

 

I have the same issue. I'm thinking its wiper motor relay. Having a hard time replacing it. If you figure out what is the cause - please post your update here. Thanks.

 

It may be the regulator/module in the wiper motor , don't buy cheap find an AC delco OEM parts supplier , I can't imagine what a wiper motor from the dealer would cost , couple hundred maybe ?