yes,,cleans ALL ground points front & rear....& make sure alternator is clean on both contacts..neg,& pos.

The ground point is at the steering column. You need to remove the two plastic covers. The right side switch has a ground wire from switch to the screw. If the screw is loose the wipers will not shut off. Under the front vent panel is where the wiper motor resides and there is a ground wire to the cowl sheet metal. That ground can become loose as well, but usually keeps the motor from running at all. Hope this helps. Pauli

If cleaning up the fender ground points doesn't fix it....

If your steering wheel column becomes loose at its mounting to the dash board, the grounding then becomes weak and the wipers will sometimes operate uncommanded as a result of electrical feed back from other accessories, usually the horn though. Can you find any other accessary, that when turned off, also kills the wipers? If so that may be a clue as to the culprit.

Very likely. Tighten the ground terminal block(s) inside the front fenders.
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1992 745, >500k km