Intermittent Wipers: How They Work and Possible Problems

Reviewed by

Richard McCuistian, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Written by CarParts.com Research Team - Updated on April 2nd, 2024

Reading Time: 4 minutes
Summary
  • Intermittent wipers are windshield wipers equipped with an intermittent setting. Their relay is typically found in the underhood junction box/fuse panel with the other relays.
  • Symptoms of a faulty intermittent wiper include the intermittent setting not working and the wiper moving at different speeds.
  • You can check your intermittent wipers if you have a schematic and know how to read it. Otherwise, it might be best to take it to a certified professional.

Most windshield wiper switches have a low, high, and intermittent speed setting. The intermittent mode allows the wipers to stop between each wipe. This is especially helpful in light rain or misty scenarios.

What are Intermittent wipers?

Intermittent wipers are essentially windshield wipers that are equipped with an intermittent setting.

Just about every car since the ‘90s is equipped with intermittent wipers. It’s harder to find a vehicle without them than it is to find one with them.

A diagram showing the circuitry of GM intermittent wipers with a dedicated module built into the wiper motor | Image Source: Richard McCuistian

Early intermittent wipers had a dedicated module, either built into the wiper motor (as on GM platforms, like in the illustration shown) or as a separate module under the dash (like on Fords) that would time the wiper sweeps and could be adjusted to time the sweeps closer together.

But in the mid 1990s, body control modules (BCM) or generic electronic modules (GEM) on Fords with internal timers with various timer functions began to appear. These modules will typically feed reference voltage to a potentiometer built into the wiper switch. The less resistance that “pot” has, the lower the reference voltage is. This is the input that determines wiper sweep timing. That being said, some GM vehicles had a standalone intermittent wiper module deep into the 2000s model years.

Where Is the Intermittent Wiper Relay Located?

Where there is a module, there are typically relays in the circuit (sometimes three different ones) that send power to the wiper motor for its various speeds. These relays are typically found in the underhood junction box/fuse panel with the other relays.

Where there is a module, there are typically intermittent wiper relays in the circuit (sometimes three different ones) that send power to the wiper motor for its various speeds. These relays are typically found in the underhood junction box/fuse panel with the other relays.

Richard McCuistian, ASE Certified Master Automobile Technician

Some of the module-driven independent wipers will factor in vehicle speed and automatically shorten the time between wiper sweeps.

A diagram showing intermittent wipers circuitry of a 2000 Ford Ranger, which uses 2 relays | Image Source: Richard McCuistian

What are the Symptoms of a Faulty Intermittent Wipers?

When the intermittent wiper relay fails or wears out, it will show a few warning signs such as the following:

The Intermittent Setting Doesn’t Work

When the intermittent wiper relay fails, the windshield wipers won’t work when the windshield wiper switch is set to intermittent. When this issue is present, the windshield wipers can only work on high or low settings.

Note, however, that on platforms with multiple wiper system relays, symptoms may vary. If the BCM or GEM is the operational component, it will receive input from the intermittent wiper switch and will command the various relays.

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: A scan tool that can display BCM or GEM datastream (generic scan tools won’t do this) can provide a “window” into the system to see if the BCM is receiving inputs and processing outputs. Higher end scan tools with bi-directional functions can command the wiper functions. If the wipers won’t work right with the switch but will work when commanded by the scan tool, the switch or its circuits will be at fault.

The Wiper Moves at a Different Speed

Relays are electronically controlled switches, though only some intermittent wiper systems have relays. When they do have relays, the relay typically works or it doesn’t. Chances are, you use your intermittent wipers enough that you’ll be able to tell when they’re not working right, such as when the wiper moves at a different speed than normal.

How to Check Intermittent Wipers Yourself

You can check your intermittent wipers if you have a schematic and know how to read it. You can also look in your owner’s manual for pertinent fuse and relay locations. You may need to take your vehicle to a repair shop if a module needs replacing because most modules need to be initialized by a professional with special equipment.

Where to Get Windshield Wiper Motor Relays for Your Vehicle

While windshield wiper motor relays are not as crucial as the engine when it comes to your vehicle’s operation, they can still cause annoying issues. Fortunately, it’s easy to find replacements when you shop at CarParts.com, your one-stop shop for high-quality parts.

Find only the best prices when you shop from us. All our windshield wiper motor relays come with a low-price and lifetime replacement guarantee, helping you get the best value for your money.

You don’t have to wait long to get your new relays. All our parts are on hand and ready to ship from our strategically located distribution centers, so you can expect your order in as fast as two business days. Place your order using our website, or you can also dial our toll-free hotline for further assistance.

To start shopping online, fill out our vehicle selector to view direct-fit windshield wiper motor relays. Then, use the search filters to view the ones that match your preferred brand, price, and features.

Check out our windshield wiper motor relays and shop now!

About The Authors
Reviewed By Richard McCuistian, ASE Certified Master Automobile Technician

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.

Written By CarParts.com Research Team

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.

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.

View Comments

  • I was troubleshooting my wipers for this problem on my jeep. It turns out my jeep is equipped with a rain sensor and if set to automatic it runs at low speed on all intermittent unless high is selected. I chgd the sensor selection to manual and it is working properly. Apparently the automatic sensor setting over rides all speed settings except high. Might be food for thought when troubleshooting. After I figured that out, I did remember changing the setting while checking out my extras. Oops :). If you covered that in your article, I apologize, I missed it.

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CarParts.com Research Team and Richard McCuistian, ASE Certified Master Automobile Technician