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Quick Overview
Having windshield wipers that won’t turn off can be annoying and even dangerous. Here are some quick tips on what to do:
– Check the wiper control arm – Make sure it is properly engaged in the off position. Gently move it back and forth.
– Check the wiper motor – The motor may be malfunctioning, preventing the wipers from turning off.
– Check the wiper relay – A faulty relay can cause the wipers to get stuck on. The relay is usually located in the fuse box.
– Disconnect the wiper motor – If nothing else works, disconnect the wiper motor wiring harness connector under the hood.
What Causes Windshield Wipers to Stay On?
There are a few common reasons why windshield wipers may get stuck in the on position:
Wiper Control Arm Issue
The wiper control arm allows you to manually switch between wiper settings. If this arm is not properly engaged in the “off” position, it will tell the wipers to keep running. Over time, the splines on the control arm can wear down and prevent proper contact in the off setting.
Faulty Wiper Motor
The wiper motor contains the electric gears that power the windshield wiper movement across the windshield. If the motor malfunctions or fails, the wipers can get stuck in one position. Motor issues are common in older vehicles.
Problems with the Wiper Relay
The wiper relay is responsible for delivering power from the vehicle’s fuse box to the wiper motor. If this relay shorts out or fails, it can deliver constant power to the wipers even when they should be off. The relay is usually located in the fuse box.
Electrical Short
Sometimes a short in the electrical wiring that powers the wiper system can bypass the control arm and relay and deliver constant power to the wiper motor. This may cause the wipers to run even with the control in the off position.
Low Washer Fluid
Some newer vehicles have a safety feature that turns on the wipers when the washer fluid is low. This could activate them even when the control is off. Be sure to check washer levels before troubleshooting wiper issues.
How to Diagnose the Issue
Here are some steps to diagnose exactly why your windshield wipers are stuck on:
Inspect the Wiper Control Arm
With the vehicle off, manually move the wiper control arm into the off position. Check that it settles and latches properly in the detent. If it feels loose or does not latch, the splines are likely worn down. This allows the arm to make poor contact in the off setting.
Check for Power to the Motor
Turn the wipers on to low speed. Carefully remove the plastic cover under the hood to access the wiper motor. With the wipers on, test for power at the motor wiring harness connector using a multimeter. If you still have power with the control off, there is an electrical issue.
Test the Wiper Relay
Locate the wiper relay in the fuse box, usually labeled clearly. Swap it with a known good relay of the same amperage rating. If the wipers now turn off properly, the original relay was bad and needs replacement.
Look for Electrical Shorts
Visually inspect the wiring harness leading to the wiper motor. Look for any damaged insulation that could be letting bare wire contact metal and short. Shorted wires that bypass the switch can activate the wipers.
Check Washer Fluid Level
Fill up the washer fluid reservoir if it is low. Topping it off may deactivate the automatic wipers if they were triggered by a low fluid level sensor.
How to Manually Stop Stuck Windshield Wipers
If you need to urgently stop malfunctioning windshield wipers that are stuck on, here are a few options:
Turn Off the Wipers at the Control Arm
Try cycling the wiper control arm into the off position multiple times. Move it slowly and firmly to allow the splines to properly engage. This may temporarily stop the wipers by interrupting power.
Remove the Wiper Motor Fuse
Locate the wiper motor fuse in the vehicle’s fuse box, typically inside the cabin. Removing this fuse will stop power flow to the motor and cease wiper movement. Use this if cycling the control arm does not work.
Disconnect the Wiper Motor Wire Harness
Pop off the plastic cover under the hood to reach the wiper motor. Unplug the wiring harness connector leading into the motor assembly. This immediately cuts off power and stops the wipers from running.
Remove the Wiper Relay
As mentioned before, the wiper relay sends power to the motor. Removing the relay from the fuse box is an easy way to stop the wipers temporarily if you cannot access the motor wiring.
Pull the Wiper Fuse
The final option is to pull the main wiper fuse in the fuse box under the hood. Like other fuses, this will cut off all power and stop wiper operation immediately. Use care when removing fuses.
How to Repair Stuck Windshield Wipers
To get your windshield wipers functioning properly again, you will need to repair the specific issue causing them to get stuck on. Here are some tips:
Replace the Wiper Control Arm
If wiper arm engagement is the problem, the entire control arm assembly will likely need replacement. You can order replacement parts online or through a dealership. Installation is simple with basic tools.
Replace the Faulty Wiper Motor
For a bad wiper motor, the best fix is to replace it entirely. You can either buy a new motor or send the old one for professional rebuilding. Replacing the motor requires removing trim panels under the hood.
Install a New Wiper Relay
A faulty wiper relay just needs a quick swap out. Buy an new relay that matches the amperage and pin-out of the old one, and insert it into the fuse box in the original relay’s place. Relays cost around $10-25.
Repair Electrical Shorts
Check all wiper wiring for damage, fraying, or bare segments that could be shorting. Repair any identified shorts with electrical tape or replacement wiring. This will stop stray current from activating the wipers.
Refill Washer Fluid
If the wipers were triggered by low washer fluid, be sure to top up the windshield washer reservoir under the hood. Maintain the proper fluid level to avoid any false activation of the wipers.
Conclusion
Windshield wipers that become stuck can be a nuisance, but identifying the cause allows you to get them functioning again. Typical issues include worn wiper arms, bad relay or motor, electrical shorts, and low washer fluid. Try cycling the wiper arm and fuse box first to stop the wipers. Then you can complete the appropriate repair such as replacing parts or wiring. With proper troubleshooting and diagnosis, stuck wipers can be easily fixed.
| Issue | Solution |
|---|---|
| Wiper control arm not engaging properly | Replace wiper control arm assembly |
| Faulty wiper motor | Replace or rebuild wiper motor |
| Bad wiper relay | Replace relay with new matching unit |
| Electrical short in wiring | Repair wiring insulation and shorts |
| Low washer fluid | Refill washer fluid reservoir |