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Summary
  • Common reasons why windshield wipers won’t turn off include a faulty control switch and a faulty relay.
  • Park switch issues and wiring concerns can also cause your windshield wipers to malfunction.
  • If your windshield wipers won’t turn off, contact a trusted mechanic. A professional will usually inspect the motor, switches, and relays to identify the fault.

Windshield wipers are a vital part of any vehicle. They make it easier to drive during inclement weather by keeping your windshield free from rain, fog, and debris. However, wipers that won’t turn off aren’t helpful at all. They can even be distracting, especially when you don’t need to use them.

How Do Windshield Wipers Work?

While the design varies depending on your vehicle’s make and model, most systems function the same. Older vehicles without intermittent wiper function simply have a gearbox and motor, which are wired to the wiper switch. The motor will have a “park switch” that remains closed after the main switch is turned off until the wipers are at their park position.

diagram of a windshield wiper system
Some windshield wiper systems, as these diagrams show, have a module that takes input from the wiper switch and then uses relays to send power to the motor on its low and high settings. Interval wipers are typically controlled by this module, or there may be a module either built into the wiper motor or as a stand-alone unit. | Image Source: Richard McCuistian

In some vehicles, the headlights also turn on whenever the wipers are on because the headlights are supposed to be on whenever it’s raining according to the traffic laws in many states.

Common Causes of Faulty Windshield Wipers

Inoperative or always running windshield wipers aren’t only a big nuisance, they’re also a big safety issue.

Here are a few common reasons behind bad windshield wipers that you can look out for.

Faulty Control Switch

A faulty control switch can be the reason behind a windshield wiper that won’t turn off. The control switch lets you start, stop, and change the speed of the wiper. If the switch has any electrical issues, then you most likely won’t be able to turn off your wipers.

To check if this is the issue with your wipers, try changing your wipers’ speed. If the speed doesn’t change, then the switch is most likely the problem. When this happens, it’s best to replace the windshield wiper switch immediately.

Park Switch Issues

Inside the wiper motor is a different type of switch called the park switch. It allows the motor to keep running until the blade returns to its resting position. If the park switch is broken, then the motor won’t know when to stop and your wipers won’t turn off as long as the key is on because the wire that feeds the park switch has power whether the regular switch is on or not.

This, however, almost never happens. Usually, when the park switch fails it will cause the wipers not to park on their own or it will cause them to park somewhere they’re not supposed to.

When the park switch fails, it will cause the wipers not to park on their own or it will cause them to park somewhere they’re not supposed to.

Richard McCuistian, ASE Certified Master Automobile Technician

If this is the issue, you need to replace the entire motor. The park switch of most vehicles is built into the motor, so you won’t be able to replace it separately.

Wiring Concerns

When the motor’s wiring or connectors are compromised with open circuits, shorts to ground or each other, etc., the wipers might continue to run even though the switch is in the off position due to power or ground being delivered from an alternate source. More often, this will prevent the wipers from working on one or more speeds or might prevent them from parking when they’re turned off.

This can happen because the wires are loose, frayed. The connectors might be loose or clogged as well.

Faulty Relay

If your windshield wipers won’t stop, then it might be because the relay contacts are stuck closed. The relay’s exact position varies with different makes and models, but you can usually find it in the fuse box next to other relay switches.

hand moving windshield wipers switch
A faulty control switch is usually the reason behind a windshield wiper that won’t turn off.

Why Are Windshield Wipers Important?

Having broken windshield wipers isn’t only annoying, it’s also very dangerous. Driving with windshield wipers that won’t turn off can be distracting, which increases your risk of getting into an accident.

Furthermore, wipers that won’t stop can also cause wear and tear on the blades. Increased use of the wipers on a clean and dry windshield causes the blades to drag against it, which means you’ll have to replace them sooner.

How To Turn Off Windshield Wipers

, Why Your Windshield Wipers Won’t Turn Off

Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.

Pro Tip: Always check the fuses first. Get a map of the fuse panel and inspect every fuse related to the wipers. You can waste a lot of time on other parts of the system only to discover a blown or missing fuse. Don’t neglect to check for fuses that are missing.

If your windshield’s wipers won’t turn off, ask a trusted mechanic to inspect your vehicle.. They will most likely check the motor, switches, and relays to properly identify the source of the issue. However, this isn’t always an available option, especially if the problem suddenly occurs when you’re on the way to work or an important appointment. 

If this is the case, find a safe place to park. Then, turn off the engine, which should also force the wipers to stop. You can disconnect the battery’s negative terminal to cut off the wipers’ power supply and reset the computer. After waiting for 10 to 20 minutes, you can restart the engine again, and the issue might be resolved temporarily, but it’s not at all likely.

, Why Your Windshield Wipers Won’t Turn Off

Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.

Pro Tip: You can also try removing the wiper fuse to stop the wipers from running all the time until you can get them repaired. Check your vehicle owner’s manual for its location. Of course, if it starts raining, you’ll need to stop and put the fuse back in so you’ll have wipers. If you do this, make sure you park in a safe place.

About The Authors
Written By Automotive and Tech Writers

The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

Reviewed By Technical Reviewer at CarParts.com

Richard McCuistian has worked for nearly 50 years in the automotive field as a professional technician, an instructor, and a freelance automotive writer for Motor Age, ACtion magazine, Power Stroke Registry, and others. Richard is ASE certified for more than 30 years in 10 categories, including L1 Advanced Engine Performance and Light Vehicle Diesel.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

File Under : Car Body , DIY
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