Wiper Motor FAQs in 2020

The wiper motor is the heart of automotive windshield wiper systems. Although unseen, it powers the wiper linkages to clean the windshield. In some regions, it’s also called the windscreen wiper motor. Check out this question and answer content about the component. The questions capture every aspect of car wiper motors, from how they operate to the cost to replace them.

Q1. What is a wiper motor made of?

The typical wiper motor assembly consists of a dc motor and transmission system called wiper motor gear box. The motor itself is a steel housing enclosing permanent magnets, a rotor coil, and commutator. At one end of the housing is a bearing and end plate. The plate also holds the motor brushes. Attached to the motor, the gearbox comprises a plastic housing and gear reduction setup. The motors shaft extends into the gearbox, with its end forming a spiral gear.

Q2. How does a wiper motor work?

The windshield wiper motor is normally installed on the firewall. From there, it connects with the wiper transmission, which is a system of rods, arms, and joints. When the wipers are switched on, the motor spins and rotates a crank arm. The arm then moves the wiper blades across the windshield, helping to remove water, dirt, snow, and other debris. Some vehicles have an additional rear wiper motor. This motor is usually mounted on the rear window to power the rear window wipers.

Q3. How powerful is a windshield wiper motor?

Car wiper motors are quite powerful. They draw a considerable amount of current and contain a set of gears to multiply torque. Typically rated 12V or 24V, wiper motors use around 5A when running freely and higher when under load. Wiper motor power or torque is usually indicated in N/M². The torque to choose mostly depends on the length of wiper arms or blades. For lengths below 16″, 8Nm would be a perfect choice. A 12Nm torque suits up to 20″ wiper arms, while 30Nm works well with up to 28″ long wipers, and so on.

Q4. What is a wiper motor park switch?

The wiper park switch controls the parking of the wipers. In other words, it ensures the blades end up in the correct resting position when you switch them offs. The switch works by powering the motor until the wipers reach the “home” position. If it goes bad, wipers stop in wrong position, usually on the windshield and obstructing your view. The switch is often built into the wiper motor gearbox.

Q5. Why is my windshield wiper motor not working?

There are many reasons. Under normal conditions, a wiper motor is meant to last a vehicle’s lifetime. In most cases, though, that does not happen. Among the causes of early windshield wiper motor problems are; frequent use, especially if you regularly drive in wet or dusty conditions, using the wipers on a dry or extremely dirty windshield and straining the motor, and switching on the wipers to clean a snow or ice covered windshield

Other causes include the wipers not starting on the park position and stressing the motor, grease drying up and causing wiper motor parts to wear too rapidly, and faulty parts of the motor and wiper system such as blown fuse, bad relay, or failing connectors and switch. All these situations stress the wiper motor, leading to its rapid wear. In some cases, the motor may even burn out and require replacing.

Q6. What are the symptoms of a bad windshield wiper motor?

Signs of a broken wiper motor often show as windshield wiper problems. The wipers may operate abnormally or fail to work whatsoever. Here is how to tell if a wiper motor is bad. The motor is failing if you have:

  • The windshield wiper not working
  • Wipers moving slower than usual
  • Wipers only operating at one speed (highest speed)
  • The windshield wipers stop in wrong position
  • Noisy wiper motor

Once you suspect that you have a bad wiper motor, it’s necessary to take action right away. You don’t want to find yourself caught in a rain or dusty weather but with the wipers not working.

Q7. How do you test a wiper motor?

Knowing how to test a wiper motor is one of the ways to troubleshoot a failing wiper system. You can use several methods to do that. One of the easiest (and most accurate), is using a digital multimeter to check for voltage. In this wiper motor testing method, the multimeter is set to read volts and the probes inserted in the motor connector terminals. If the multimeter indicates a voltage, the motor is probably faulty. If it doesn’t, there could be a problem with the motor’s wiring system. You may go ahead to check the power circuit, sensors, control module, relay, fuse, and other electrical parts.

Q8. Is wiper motor repair worth the costs?

It depends. In some cases, it is. In others, replacement offers a more logical solution. Windshield wiper motor repair entails replacing faulty parts with new ones and costs between $20 and $100. On the other hand, wiper motor replacement costs around $100 to $200. This amount includes the wiper motor assembly price and the mechanic’s rates. When deciding whether to repair or replace a motor, consider the type of components that you need to change and their cost. That will help you make a sound decision.

Q9. Can I replace a windshield wiper motor myself?

You can. The wiper motor location in engine bay makes it easy to work on. You only need a ratchet and socket set and the steps to remove and install the motor. If you know how to replace a windshield wiper motor, you could save up to $200 in costs. In the end, you will only have spent around $50 to 300$, which is the price to buy a new wiper motor assembly. A rear wiper motor is often a little more complicated to replace. There are more components to get out of the way and the delicate window to worry about.

What are the options when buying wiper motors for cars?

You should always purchase the wiper motor that matches your car details. Apart from that, there are different versions of the motor or features to consider. You could also be looking to change the motor to a better one and searching for specific details. Options when buying car wiper motors include OEM or aftermarket versions, 12V or 24V rating and front or rear. Other important factors include:

Most of the time, the size of the wipers determine the wiper motor specifications to go for. It’s also worth noting that OEM wiper motors are generally more costly than the aftermarket types.


Windshield wiper motors are important parts in your car or truck. Without them or if broken, you would have a hard time driving in rainy or dusty conditions. The wiper blades would not work, leading to visibility problems and making your car unsafe to drive. The questions answered here are meant to improve your understanding of the wiper motor so you can easily ensure its working.

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