Windshield wiper motors do not require a lot of maintenance. However, just like any other part on your engine, they do eventually wear out and need replacing. Wiper motor replacement is fairly easy with the right tools and safety considerations. Windshield wiper motors are capable of overcoming the binding effects of ice on the wiper blades and accumulated debris on the wipers.
Locate the windshield wiper motor. It is usually mounted to the vehicle's firewall between the engine and driving compartment. If you have trouble locating it, consult the service manual for your year and model vehicle. The manual will show you the exact location of the wiper motor.
Use a fused jumper wire to bypass the motor's relay once you have located the wiper motor. Use your service manual to locate the relay. Hook one side to the positive battery terminal and touch the other end to the positive on the wiper motor. If the motor works and the arms move, replace the relay.
Use the positive lead on your jumper wire to touch the positive terminal on the relay. If the motor works, you will need to check the gear mechanism inside the motor assembly. If it does not work, continue with the removal and replacement procedures that follow.
Locate the grounding strap. One end of the grounding strap is secured to the motor case with a bolt or screw. The opposite end is secured to one of the wiper motor mount bolts. Once you have located the grounding strap, remove the mount bolt it is grounded to using your open-end box-end wrench or ratchet set. Move the ground strap out of the way so it does not get stretched or damaged.
Remove all other mount bolts (varies from car to car). Gently pull the washer motor away from the mount and remove from the engine compartment.
Line up the mount holes on your new washer motor with the mount bolts on the firewall. Push the motor onto the mount bolts and secure in place with the mounting nuts. Tighten nuts in a star pattern so the washer motor is flush against the firewall. Reinstall the wiper motor grounding strap.
Use your fused jumper wire to test the new motor's operation. The motor should turn freely. If not, the new part is defective. Return it to the vendor you bought it from and get a new one.
Disconnect the jumper wire leads. Install the connector to the relay. Check motor operation from the switches on the driver's console.
Do not damage mount bolt threads when removing the motor or installing it. Thread damage will require an involved replacement process. Take care not to cross thread the mounting nuts for the same reason. Use a bumper cover to prevent damage to the vehicle's paint finish. Check the wiper motor fuse before you begin this procedure.
Make sure the wiper arms are in their parked position and the new motor is in the parked position.