Have you checked UNDER the Wiper motor itself in that plastic frame unit its bolted to ? There is a WATER DRAIN there. If its plugged your electric motor will be sitting in a pool of water after a rain.
The opening is the size of a Quarter and is front facing on the side of the plastic frame unit so it will be easy to tell if its filled with leaves or gunk once you have the wiper motor out. IF you dont see said opening then IT IS :)
This is my bet as I had same situation. The water would slowly drain but oneday it plugged solid and I found it.
I quick test with a garden hose or a quart of water from a mop bucket poured near the wiper motor to see if it drains fast will be all the test you need. Should be quick with a quarter size hole opening that it has. Use care of course not to intentionaly get the wiper motor wet.
Hope this helps
Wednesday, February 11th, 2009 AT 8:58 PM