You can check the switch by unplugging the harness at the motor and checking for key-on voltage on pin 3 (gray wire). If voltage is on the pin when the wiper switch is off, the switch is bad.
If the switch is good the problem may be caused by a partially shorted diode (CR1) or other problem on the pulse board. Best way to test is by substituting a known good board.
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11:19 PM
Mar 23rd, 2010
deezil Member
Posts: 779 From: St Louis Mo USA Registered: Mar 2010
I'll bet the problem is in your controller board. There are a couple of high current diodes on it which much work to allow current to operate the wiper motor, and they must stop reverse current, or else your wiper will intermittently make a swipe. When I found the offending diodes on my controller board, I replaced them, then found that they would do this intermittent swipe. I had to try some of the others in the package until I found a pair that would work properly. They come 4 to a pack, and you'll need 2. They are (or were) available at Radio Shack.
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01:26 PM
Boostdreamer Member
Posts: 7175 From: Kingsport, Tennessee USA Registered: Jun 2007
The shaft inside the switch can also rotate too far and get stuck in a diferent position so when you think you have it turned all they way, it is on the outside but not internally. I had that problem for a while and I seem to remember having to force it one direction to get it back. I can't remember if I did that with the switch taken apart. I know I did have it apart while I was trying to figure out the problem. Too long ago so don't ask for details. Don't say I advised you to try it either. Just saying what I did.
Jonathan
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02:53 PM
Mar 24th, 2010
outlawfiero17 Member
Posts: 1450 From: sacramento, CA Registered: Jul 2009
also dont just assume that just cause the motor turns its good. i changed everything (switch and went threw 8 boards) all giving me the same result. turns out my motor had a dead spot and didnt know when or where to stop. so that is still a possibility.
