Tugging on the wiper arms is what I would have suggested, and since that made the wipers work, that proved the motor is okay. If you look at the plate the motor is mounted on, you will see there is a brass strip riveted to it, and the other end is under the head of one of the three mounting bolts. That is the ground strap. It is needed because the plate is mounted on rubber isolator bushings to reduce vibration being felt inside the vehicle. It has arced away under the bolt head.
Find a bolt on the motor's gear housing or find or drill a hole in the plate where you can run in a self-tapping screw. Attach a ground wire to that bolt or screw, then attach the other end to a paint-free point on the body. Fixed!
Wednesday, June 28th, 2017 AT 7:41 PM