Yea, it's pretty funny. Then again, it's not my car.
My fiancee's problematic Saturn SL2 has yet another little, nagging problem, in that the wipers, once turned off, will continue to run. For instance, if you hit them just to clear a little road spray, they choose to stay on for a couple of minutes. Or an hour.
Bad ground? That's the only thing I can think of.
We had an old pontiac transport van that had the same issue. It turned out that the switch had gotten corroded/gunked up and made contact between terminals despite being in the off position. Its a hard switch to get to though. Dad only had access to it because one day when mom went to turn, the whole steering column rotated rather than just the wheel. If you can get to the switch, try to clean it with some isopropyl alcohol to remove said booyah from the terminals.
bad park switch in the wiper motor itself?
check to see if power continues going to the motor with the switch off. If it does then check back at the switch for problems. If power from the switch turns off with the switch then I Blame the park switch in the motor.
Just fixed the same problem on Mini Jr.old Prizm. I located the correct power wire at the plug on the wiper motor and spliced in a toggle switch mounted on the dash. It took about 35 minutes, start to finish. He doesn't want to spend any money on this car- it only has to make it until June. BTW, this old Prizm(1996)is amazing. It's been severely neglected and pounded mercilessly, and continues to purr like a kitten!
when it happens tap the cover on the wiper motor itself and see if they stop.
the gm truck motors liked to run with a mind of their own when the circuit board inside the motor itself would get corroded. fix is replace motor.
