On Mode
WARNING: This page is about a different car, the 2003 Ford Pickup, 2003 Ford F550 Super Duty, 2003 Ford F450 Super Duty, 2003 Ford Excursion, and 2003 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
Test the on mode by connecting a separate set of test leads from battery ground (-) post to windshield wiper motor (4) component side pins 6 and 7 (6). When these pins are grounded, the rear window wiper motor operation should now be in on mode.