Top Symptoms of a Faulty Windshield Wiper Motor: Diagnosis, Causes, and Solutions

Symptoms Of A Bad Windshield Wiper Motor

If you want to maintain a clear view of the road while driving, having properly functioning windshield wipers is crucial. When your windshield wiper motor starts to show signs of trouble, it’s essential to address the issue promptly to ensure your visibility doesn’t suffer.

Here, we’ll explore the most common symptoms of a bad windshield wiper motor and guide you on how to identify and resolve the problem.

1#. Wiper Blades Moving Slower Than Usual

One of the primary indicators of a failing windshield wiper motor is when your wiper blades begin to move at a slower pace than they typically do.

Most modern vehicles come equipped with windshield wipers that can operate at various speeds, allowing you to adjust them according to the intensity of the precipitation.

If you notice that your wipers are moving slowly when set to a higher speed or vice versa, it may be a sign of motor trouble. This issue can arise due to internal mechanical components in the motor becoming contaminated with debris or dirt.

When such contamination occurs, it can impede the motor’s ability to operate at the desired speed. It’s crucial to address this promptly by cleaning off the debris to prevent further wear and potential motor failure.

#2. Wiper Blades Move Only at One Speed

Another common symptom of a bad windshield wiper motor is when the wiper blades only operate at a single speed, regardless of the speed setting you select. The wiper motor receives signals from the control module, and if either the motor or the module malfunctions, it can result in this issue.

Therefore, before replacing any components, it’s essential to perform diagnostic tests to pinpoint the source of the problem accurately.

#3. Wiper Blades Stop Moving Completely

In some unfortunate situations, your wiper blades may come to a complete stop, leaving you with no way to clear your windshield while driving.

You might hear the wiper motor attempting to function, or it may remain silent. When this occurs, time is of the essence as driving with obstructed visibility is extremely hazardous.

While a bad motor is a common culprit for this problem, it’s essential to consider other potential causes, such as a blown fuse.

A blown fuse typically occurs when there is excessive resistance within the circuit, often due to underlying defects. If your wipers are still moving, albeit slightly, the fuse may not be the issue, and you should explore other possibilities.

#4. Wiper Blades Won’t Stop in the Correct Position

Ideally, when you turn off your windshield wipers, they should return to the parked position, typically at the bottom of the windshield or as designated by the automaker.

If you find that your wipers do not return to this correct position after turning them off, it indicates a problem. Wipers that remain in your field of vision when switched off can impair your ability to see the road clearly.

While you may still be able to manually operate the wipers using the switch, they will consistently return to an incorrect park position. Conversely, if the wipers get stuck in the upright position and refuse to operate at all, a blown fuse may be the cause.

#5. Humming Noises

In many cases, the aforementioned symptoms may be accompanied by a humming noise emanating from the wiper motor.

Even if the motor is entirely non-functional, it may still receive power from the vehicle, resulting in this humming sound. If you listen closely near the motor, you may hear it more distinctly.

If your wipers are still operational but you detect this noise, it may be wise to consider replacing the motor to prevent an imminent failure. Now that you’re familiar with the common symptoms of a bad windshield wiper motor, let’s delve into the function of this essential component.

What’s The Function Of A Windshield Wiper Motor?

The windshield wiper motor serves as the “brains” behind your windshield wipers, functioning as the driving force for the wiper blades. It generates the necessary torque to move the wipers across the windshield, effectively clearing it of rain, debris, or any obstructions.

Conveniently located near the wiper blades, the motor operates the wiper mechanisms without the need for excessive additional components. Here’s a breakdown of how the wiper blades work in most vehicles:

You initiate the windshield wipers by using the control stalk located near your steering wheel.
This switch sends a signal to the electronic control module within the wiper motor assembly.
The module then manages circuits that instruct the motor on how to proceed.
These circuits and relays transmit voltage to the windshield wiper motor.
The wiper motor contains a wire winding or “winch” as part of its construction. When energized, this component generates the force required to set the armature into motion.
The spinning armature initiates the rotation of a shaft that houses either a spiral or worm gear.
This rotational movement causes a plastic wheel winch with teeth to rotate.
The winch, in turn, engages the pinion gear, creating rotational motion that drives the pushrod or short arm through a to-and-fro action.
The short arm is directly linked to the wiper linkage, enabling smooth movement of the wiper blades across the windshield surface.

In some modern vehicles, advanced wiper systems automatically activate when precipitation begins to fall. These “rain-sensing wiper blades” are controlled by the motor’s electronic module, which works in tandem with rain sensors integrated into the windshield.

Additionally, all contemporary wiper blades include a circuit that guides them back to the parked position when you switch off the wipers, regardless of their position in the cycle.

What are the Signs of a Bad or Failing Windscreen Wiper Motor?

Signs of a bad or failing windscreen wiper motor include:

Slow wiper blade movement compared to the selected speed settings.
Wiper blades operating at a single speed, regardless of the control setting.
Complete cessation of wiper movement, leaving the windshield uncleared.
Wipers failing to stop in the designated park position when turned off.
Audible humming noises from the motor even when the wipers are not functioning correctly.

What Causes Windscreen Wiper Motor Problems?

Windscreen wiper motor problems can be caused by various factors, including:

Blown Fuse: A blown fuse, often due to excessive resistance in the wiper circuit, can disrupt wiper operation.
Motor Contamination: The motor’s mechanical components may become contaminated with debris or dirt, leading to reduced speed.
Electrical Malfunctions: Electrical issues within the motor or associated components can affect wiper performance.
Mechanical Failures: Internal mechanical failures within the motor can result in wiper motor problems.
Wiper Linkage Issues: Damage or misalignment in the wiper linkage can hinder proper wiper movement.
Worn or Faulty Wiper Switch: The control switch responsible for regulating wiper speed and function may develop defects.
Relay Failure: Failure of the relay responsible for sending electrical power to the wiper motor can disrupt wiper operation.
Wiper Blade Condition: Worn or damaged wiper blades can affect their efficiency and strain the wiper motor.

Where Is The Windshield Wiper Motor Located?

The majority of windshield wiper motors are situated on the car’s firewall—a structural barrier positioned between the vehicle’s engine compartment and the cabin. In most instances, accessing the windshield wiper motor is relatively straightforward, but this may not always be the case.

If you encounter difficulties locating the motor, a helpful approach is to trace the various parts of the windshield wiper system. If this method proves ineffective, consulting your vehicle’s service manual can provide valuable guidance.

How Much Does It Cost To Replace A Windshield Wiper Motor?

The cost of replacing a windshield wiper motor can vary based on several factors:

Wiper Motor Price: The price of the windshield wiper motor itself typically ranges from $50 to $225, depending on your vehicle’s make and model.
Labor Costs: Labor costs for the replacement job can vary by location and the mechanic’s hourly rates. On average, you can expect to pay an additional $100 to $175 for labor.
Total Replacement Cost: Taking into account both the wiper motor price and the labor costs, the total replacement cost averages between $150 and $400.

It’s essential to note that these costs can vary significantly depending on the specific vehicle and the mechanic or service center you choose. Therefore, it’s advisable to obtain quotes from different service providers to ensure you get the best price.

Bad Windshield Wiper Motor: How to Recognize and Repair

For a comprehensive understanding of recognizing and repairing a bad windshield wiper motor, please refer to the previously provided information in the main article. It covers the common symptoms of a bad wiper motor, its function, and steps to diagnose and address the issue effectively.

5 Common Windshield Wiper Motor Problems

Here are five common problems associated with windshield wiper motors:

#1. Slow Wiper Blade Movement

Symptom: Wiper blades move slower than usual.
Possible Cause: The motor’s mechanical components may be contaminated with debris or dirt, leading to reduced speed.
Solution: Clean the contaminated parts and address any obstructions to restore proper wiper blade movement.

#2. Single Speed Operation

Symptom: Wiper blades function at only one speed, regardless of the setting.
Possible Cause: This issue may stem from a problem with either the wiper motor or the control module that sends signals to it.
Solution: Perform diagnostic tests to determine the specific source of the problem before considering replacement.

#3. Wipers Stop Moving

Symptom: Wiper blades cease movement entirely.
Possible Causes: A faulty motor or a blown fuse can lead to this problem.
Solution: If there is no wiper movement at all, check the fuse first. If the wipers move slightly, the motor may need replacement.

#4. Incorrect Park Position

Symptom: Wipers do not stop in the correct park position when turned off.
Possible Cause: This issue may compromise visibility as the wipers obstruct the view.
Solution: If the wipers do not return to the designated park position, consider motor replacement.

#5. Humming Noises

Symptom: A humming noise is audible even when the wipers are not functioning correctly.
Possible Causes: The motor may still receive power, resulting in the humming sound.
Solution: If you hear this noise and the wipers exhibit abnormal behavior, it’s advisable to replace the motor before it completely fails.

What Causes Windshield Wipers to Not Work?

Several factors can cause windshield wipers to fail:

Blown Fuse: When there is excessive resistance in the wiper circuit, often due to another defect, the fuse can blow. This safeguards the system but must be replaced with a fuse of equal amperage.
Wiper Motor Issues: As discussed earlier, various motor problems can hinder wiper operation, such as contamination, electrical malfunctions, or mechanical failures.
Wiper Linkage Problems: Damage or misalignment in the wiper linkage, which connects the motor to the wiper arms, can prevent proper movement.
Faulty Wiper Switch: The control switch that regulates wiper speed and function may develop defects, leading to erratic wiper behavior.
Wiper Relay Failure: The relay responsible for sending electrical power to the wiper motor can fail, disrupting wiper operation.
Worn Wiper Blades: Over time, wiper blades can deteriorate or become misshapen, reducing their effectiveness.
Faulty Park Switch: A malfunctioning park switch can prevent the wipers from returning to the correct park position.

To resolve wiper issues, it’s crucial to diagnose the specific problem accurately and address it accordingly, whether through repairs or component replacements.

Bad Wiper Motor Symptoms

Here are common symptoms indicating a bad windshield wiper motor:

Slow Wiper Blade Movement: Wiper blades move at a slower pace than expected, affecting their ability to clear the windshield effectively.
Single Speed Operation: Wiper blades function at a single speed setting, regardless of adjustments, indicating a potential issue with the motor or control module.
Wipers Stop Moving: The wiper blades come to a halt, either intermittently or entirely, while the motor may still be operational.
Incorrect Park Position: Wipers do not stop in the designated park position at the base of the windshield when turned off, obstructing the driver’s view.
Humming Noises: A humming sound is audible from the wiper motor, even when the wipers are not functioning correctly, indicating potential motor problems.

Recognizing these symptoms early and addressing them promptly is essential to ensure safe driving conditions and visibility during inclement weather.

Diagnosing a Faulty Windshield Wiper Motor

To diagnose a faulty windshield wiper motor, follow these steps:

#1. Check the Wiper Fuse

Locate the wiper motor fuse and inspect it for any signs of damage or if it’s blown.
If the fuse is blown, replace it with a fuse of the same amperage rating.
If the new fuse blows again, it may indicate an electrical issue within the wiper motor.

#2. Inspect the Wiper Linkage

Remove the cowl or cover to access the wiper motor and linkage.
Examine the connections and linkage for any visible damage or debris.
Clean off any debris and replace any damaged components.

#3. Test the Motor Circuit

Use a digital multimeter to test the motor circuit according to the specifications outlined in your service manual.
If the readings are within the specified range, the circuit may be functioning correctly.
If not, it may be time to consider replacing the wiper motor.

Replacing a Busted Wiper Motor

Replacing a malfunctioning windshield wiper motor involves the following steps:

#1. Gather Tools and Materials

Ensure you have the necessary tools and a replacement wiper motor on hand.
Common tools include wrenches, screwdrivers, and a multimeter.

#2. Disconnect the Battery

Disconnect the vehicle’s battery to ensure safety during the replacement process.

#3. Remove the Cowl

Access the wiper motor by removing the cowl or protective cover, typically located near the base of the windshield.

#4. Disconnect Electrical Connections

Carefully disconnect any electrical connections and wires leading to the wiper motor.

#5. Remove Mounting Bolts

Unscrew and remove any mounting bolts securing the wiper motor in place.

#6. Detach the Wiper Arms

Disconnect the wiper arms from the motor shaft. Some wipers may have a retaining nut or clip that needs removal.

#7. Remove the Old Motor

Carefully lift out the old wiper motor from its housing.

#8. Install the New Motor

Place the replacement wiper motor into the housing and secure it with mounting bolts.

#9. Reattach Wiper Arms

Reconnect the wiper arms to the motor shaft and secure them in place.

#10. Reconnect Electrical Connections

Reconnect any electrical connections and wires to the new wiper motor.

#11. Test the Wipers

Reconnect the vehicle’s battery and test the wipers to ensure they operate correctly at various speeds.

#12. Replace the Cowl

Reinstall the cowl or protective cover.

#13. Final Check

Conduct a final check to ensure the wipers stop in the correct park position and work smoothly.

How Do You Test A Windshield Wiper Motor?

Diagnosing issues with the windshield wiper motor is a relatively straightforward process. Several diagnostic steps can help you pinpoint the problem:

Begin by inspecting the wiper motor fuse. Consult your vehicle’s service manual to identify the fuse’s location. If the fuse is blown, replace it with one of the same amperage. If the fuse continues to blow, it may indicate an electrical malfunction within the motor.
Examine the wiper linkage by removing the cowl to access the wiper motor and linkage. Check the connections and remove any debris. If you identify any damaged components, replace them and observe whether the wipers function correctly.
Test the motor circuit using a digital multimeter. The service manual should provide instructions and recommended readings for this test. If the circuit appears to be functioning correctly, it may be time to consider a new wiper motor.

While working on windshield wiper motors is generally not overly complicated, some issues may appear challenging to resolve. In such cases, seeking the assistance of a professional mechanic is advisable. Take the time to find a reliable auto mechanic to address the problem effectively.

FAQ: Windshield Wiper Motor Issues

How Can I Tell If My Windshield Wiper Motor Is Failing?

Common signs of a failing windshield wiper motor include:

Slow wiper blade movement: Wipers move slower than usual, even at higher speeds.
Single-speed operation: Wipers only work at one speed regardless of settings.
Complete cessation of movement: Wipers stop working entirely.
Incorrect park position: Wipers do not return to the designated park position when turned off.
Humming noises: A humming sound coming from the motor even when wipers are not operating.

What Causes Windshield Wiper Motor Problems?

Possible causes include:

Blown fuse: Often due to excessive resistance in the circuit.
Motor contamination: Dirt or debris affecting motor performance.
Electrical malfunctions: Issues within the motor or associated components.
Mechanical failures: Internal defects in the motor.
Wiper linkage issues: Damage or misalignment in the linkage.
Worn or faulty wiper switch: Defects in the switch controlling wiper function.
Relay failure: Problems with the relay sending power to the motor.

Where Is the Windshield Wiper Motor Located?

The windshield wiper motor is typically located on the car’s firewall, which is the structural barrier between the engine compartment and the cabin. If you have trouble finding it, consult your vehicle’s service manual.

How Much Does It Cost to Replace a Windshield Wiper Motor?

Replacement costs can vary:

Wiper motor price: Generally between $50 and $225.
Labor costs: Typically between $100 and $175.
Total replacement cost: Usually ranges from $150 to $400, depending on vehicle make/model and service provider.

How Do I Test a Windshield Wiper Motor?

To test the motor:

Check the fuse: Inspect and replace if necessary.
Inspect the wiper linkage: Remove debris and check for damage.
Test the motor circuit: Use a digital multimeter according to the service manual’s specifications.

What Should I Do If My Windshield Wipers Stop Working Completely?

Start by checking the fuse. If the fuse is intact, inspect the motor and linkage for any issues. If the motor still doesn’t work, it may need replacement. Consulting a professional mechanic can help diagnose and resolve the problem effectively.