windshield wiper stopping issue

wnjj wrote:

MEXICOWANDERER wrote:
Wiper motors have battery power supplied directly to the motor as well as ignition power.

When the wiper switch is turned off, the battery power continues to supply the motor with power until the wipers arrive at their resting place. Inside the gearbox is a limit switch oriented to shut the wipers down when they reach the PARK position.

A broken limit switch inside the wiper gearbox would cause this. So would a fried wiper pigtail battery power terminal. There is no way to defeat the auto park feature except to turn the key off while the wipers are in action. So, the clue is to check battery voltage at the connector to the wipers. It's time to grab a 12-volt test light and access a factory wiring diagram. Blind parts replacement try-it-and-see is a poor diagnostic substitute.

Hey Mex, I think you contradicted yourself a bit. The wiper motor has switched power (from the wiper switch) and ignition power but nothing directly from the battery. That's how you can defeat parking, like you said, by turning the key off before they park.

Regardless, the park switch is almost certainly the problem and usually means buying a new wiper motor unless you're handy enough to take it apart and clean the contacts.

That is old school wiper motors (late 1980s on down), NEWER wiper motors do have unswitched battery power applied at all times AND they have an electronic circuit board which controls speed and park of the motor..

Had a friend with a 1990s vehicle that the wipers would continue running sometimes when the ignition was turned off.. Had to pull fuse supplying power to the wiper motor, wait 10 seconds then put fuse back in.. And all was well until it did it again..