I have quite the opposite issue. My wipers will sometimes, NOT turn off. If I use intermittent or the mist function, the wipers will go to full on even with the switch turned off. I can still go to high speed but the only way to make them stop is to pull the fuse. They will continue to run even with the engine turned off. I replaced the motor and the issue continued. My local dealership swears they've never heard of such a thing.