When the rainy season rolls around, you'll certainly want to see where you're going when on the open road. Therefore, nothing is more disconcerting than a faulty wiper motor that either fails to work altogether or seems to have a mind of its own. If you're facing this problem and there is a lot of rain in the forecast, you'll want to get to the bottom of it as soon as possible. What could be going on?
At its base, the wiper motor is a simple contraption that is designed to turn gears and move the wiper blades through a predetermined arc. Yet the modern-day solution is more complex than that and allows you to choose the operational speed, an intermittent feature, automatic parking and other solutions.
To troubleshoot, figure out the symptoms and work back from there.
Sometimes, the wipers will move very slowly, and this could be due to either an electrical fault or a blockage of some kind. Check to see that the wires and connectors are still attached to the rear of the wiper motor so that they can provide the right current to the system. Also, look for any debris (such as rotting leaves in the autumn) that could be snaring the wiper linkage.
If the wiper motor does not change speed upon request, this could be due to a faulty control module. It's not something that can be repaired as such but will need to be replaced by a qualified mechanic.
Sometimes, the wipers will refuse to park at the bottom of the windscreen but may stop in the driver's field of vision. This is probably caused by a dodgy park switch. This switch is supposed to come on when you turn the main wiper switch off and rotate the mechanism to the required position. It may be simply worn out or not receiving the right amount of current. You may also need to look at the gear mechanism for signs of any digital debris and replace the park switch if needed.
No Power to the Motor
If you are getting no response from the system at all, you can test the wiper motor if you have a multimeter handy. You will need to connect the multimeter probes to the motor connector. If the part appears to be receiving power, the motor itself may be beyond repair and require replacement. If there is no power, you could be looking at a bad relay or blown fuse.
If you're still unable to figure out what's going wrong, outsource the task to a mechanic. They'll diagnose quickly, before repairing or replacing any parts as needed. Go to your local auto repair shop for more help.