98 sc2 wiper problem need help

I have a 98 sc2, car is in excellent condition. Only problem is when I
press down on the wiper stalk to mist the windshield, the wipers will
not cut off. Sometimes they will run for 10 minutes, sometimes only 15
or 20 seconds. If I push the stalk up to low no effect, but if I push
it to high, it does increase the speed of the wipers to the normal high
speed, but then when I press the stalk back down to off position, the
wipers will still not turn off.

I took the car to the dealer for another problem (service engine
soon-was worn out oxygen sensor) and there were no trouble codes
detected for the wiper problem. I checked the fuse inside the
passenger compartment (25 amp) and it is fine.

Any ideas if this is the wiper motor or is it an electrical problem at
the stalk?

Thanks in advance for suggestions.

 

Stalk is possible if the contacts for wash are sticking, but my guess is
that would also result in continuous wash as well, but might not result in
it throwing a code. Otherwise the cycling is usually controlled one of 3
ways:

1. control module (computer)
2. relay timer (older approach)
3. circuit built in to motor (even older)

Age would suggest #1, make sure that there ARE applicable codes for this
type of thing.

Check your manual to see if there is a possible relay in one of the load
centres (many cars have more than one "fuse box" now)

Good Luck