the GEM should be behind the radio in the center area of the dash.
Are you positive the GEM is bad.
the rear door latch and rear window latch has to be closed for it to send a signal for the wiper to work. they are controlled off relays in the engine compartment. IIRC
Hope we find out. Our Explorer's has been intermittent for a long time. Sometimes it works, other times it doesn't. Usually when you need it most, of course. I've chased down everything else so I'm now thinking it's the module. Lord only knows where it's located.
Mine's been sorta off and on since I got it. It wouldn't work for a while, then it would. Seemed as if opening and closing the rear liftgate (not the window) made all the difference. But this last time I've opened and closed it probably 20 times and nothing has happened. I turn the switch, it sits, then maybe 10 seconds later I hear a "click".