Dandy. If you turn on the ignition switch and the wiper switch, then find voltage on the motor's housing, you'll find the motor will start to run if you push on it.
The motor is bolted to a metal plate, and that plate is mounted on three rubber bushings to isolate vibration from going into the passenger compartment. The motor has to be grounded to complete the electrical path for current to flow. Since the rubber bushings insulate that path, a brass strip of metal is added to one of the bushings. You'll see that strap riveted to the metal plate. It's about 3/4" wide and 2" long. The other end goes under the bolt head. That is where it can arc and burn away, creating a break in the circuit, and a dead motor. You may see it spark there when you push on the motor.
It is not practical to try to repair that connection. The motor might work if you simply tighten that bolt a little, but that is not a permanent fix. Instead, run a new ground wire between that plate and the car body. There is usually some other bolt on the body, nearby, that you can attach the wire to. On the plate, look for another bolt you can use. If there is none handy, drill a small hole in the plate, then run in a self-tapping screw the wire can be attached to.
Also, if you look at the gearbox end of the motor, there will be a round, flat cover, either plastic or metal, attached to it. That is part of the electrical connector. Some of those are held on with five rivets. Many are held on with five small screws. If yours has screws, you can loosen one, then attach that end of the wire to that.
Saturday, March 25th, 2017 AT 2:14 PM