Turn the wipers and ignition switch on, (fast or slow, not delay). Use a grounded test light or voltmeter to measure the voltage on the case of the wiper motor. I suspect you'll find 12 volts or the test light will be bright. The motor might even start to run when you push on it. There are three mounting bolts holding the plate to the body. They go through rubber bushings to reduce vibration. To get a good ground, one of the bolts has a copper ground strap riveted to the plate. That strap arcs away under the bolt head. You might see it spark there when the motor starts to run.
To repair the bad ground, you'll need to run a new wire. The easiest way to do this is if the cover of the motor is held on with 1/4" bolts, attach a wire under one of them, and attach the other end under the head of one of the other two mounting bolts. If the motor cover is riveted on, you'll need to drill a hole in the mounting plate and attach the wire with a self-tapping screw.
If there's no voltage on the motor housing, measure for voltage on the wires in the connector. There should be 12 volts on two of them; one to make the motor run, and one that's hot all the time the ignition switch is on to keep the motor running to park the wipers when the wiper switch is turned off. If the voltage is missing, you have a blown fuse, defective switch, or a wiring problem. The ignition switch is known for burned contacts and melted terminals in the plug, but other things such as the radio, heater fan, and power windows would not work either.
Monday, April 27th, 2009 AT 3:46 AM