Wipers won’t run – is it the switch, or the motor, or something else?
- Verify all wires are connected according to wiring diagram, and confirm there are no loose connections.
- Check switch by one of two methods – 1) Change the switch with one from another wiper, that is working properly. If a different switch runs the motor properly, then the original switch is faulty, and needs to be replaced. 2) Connect positive and negative to the switch, and measure voltage output the for low and high speed. To check park, you should have continuity between the low speed output and the park wire when the switch is turned off. If you have no voltage output for low and high speed, when the switch is turned on to these settings, then the switch is faulty and should be replaced. Also, if you have no continuity from the low speed and the park wire when the switch is turned off, then the switch is faulty and should be replaced.
- If switch tests properly, disconnect switch from motor, and test motor manually, according to instructions on drawing “Instructions for Running Motors Manually” (see below) . If motor does not run on low speed, high speed, and park properly, and positive voltage is verified at the motor, and ground is verified at the motor, then motor is faulty and requires replacement.
- If both motor and switch test correctly, then it is a wiring problem. It is probably better to replace the entire wiring circuit than to check for faults and shorts somewhere along the circuit. A local electrical supply company should have available all of the necessary wiring.