Why a windshield washer doesn't work troubleshooting tips

December 26, 2018

The windshield washer system is fairly simple, there is a switch, the control module and the motor. The pump is attached to the motor. In some older cars the switch powers the motor directly. The windshield washer motor is located at the bottom of the windshield washer fluid bottle (tank); under the hood or inside one of the front wheel wells.
If the windshield washer doesn't work, here is how you can troubleshoot. Follow the link or the next step:

Is it below freezing outside? Yes No.
Is only one nozzle not working? Yes No, both are not working.
When you are pressing the switch, with the ignition ON, do you hear the windshield washer motor run? Yes No.

The windshield washer motor runs, but the fluid doesn't spray.

Windshield washer motor
Windshield washer motor/pump

The low windshield washer fluid indicator light not always works. The only way to know if there is enough fluid in the windshield washer fluid bottle is to check the level at the bottle or top it up if the level is not visible.
If there is enough fluid and the motor runs, check if the fluid leaks somewhere under the car. The hose that runs from the pump to the washer jets can break or get disconnected somewhere. A bottle itself can be cracked. The windshield washer bottle is not very expensive to replace: $30-$90 part plus $50-$150 labor. If there is no leaks, check if the washer fluid hose is not kinked or jammed. The common place where this happens is where it connects to the hood (if the washer jets are mounted on the hood). In winter time, the fluid can freeze in the hoses and in the washer jets. And of course, the little pump that comes together with the motor can break inside. In this case, the motor will have to be replaced.

One nozzle sprays, the other one doesn't

A nozzle can get clogged up or the hose can pop off from the nozzle. In most cars, both nozzles are mounted on the hood. If you open the hood, you might see the hose connected to the nozzle. It might be hidden under the hood sound-proof cover. If the hose came off, you will see a leak. If one of the nozzles is clogged up, it can be cleaned with a pin.

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The windshield washer fluid froze

This happens very often in below-freezing temperatures. A car may still have a summer windshield washer fluid in the washer fluid bottle. When the temperature drops, the fluid freezes. The solution is to bring the car inside a warm garage and let the ice melt. It may take several hours. Some people pour warm water on the sides of windshield washer bottle to melt the ice. Once the fluid melts and the washer pump starts working, use up all the old fluid and refill the bottle with the winter windshield washer fluid. The fluid can freeze not only in the bottle, but in the hoses and in the washer jets as well.

The motor doesn't run when the switch is operated.

Blown vs good fuse
Check the fuse first. The left fuse is OK, the right fuse is blown.

The motor is powered by the 12 Volt power when you press the washer switch. It only works when the ignition is ON or the engine is running. The first step is to check the fuse. You can find the fuse location near or on the fuse box cover or in the owner's manual. The fuse says "Washer," see the photo. In most cars there are at least two fuse boxes. One is located under the hood; the other one is inside the car. In this Honda in the photo the in-cabin fuse box is located above the left front kick panel. See: How to check a fuse in a car. If the fuse is OK, the voltage at the motor needs to be checked. See the next step.

How to measure the voltage
There is 12V at the connector. If the connector is not corroded and the motor doesn't run, the motor is bad. Click for a larger image

It's best to check the voltage while the connector is still connected to the motor. It's called back-probing. This way, if one of the wires has poor connection or corroded, the multimeter will show low or no voltage. If you measure the voltage when the connector is disconnected, even if one of the wires is badly corroded it will still show 12 Volt. This is because there is no load and therefore no current in the wire. If there is 12 Volt at the back of the motor connector (see the image), but the motor doesn't run, the motor itself could be bad. Of course the connector also must be checked as it could be corroded. Replacing the windshield washer motor is not very difficult. In most cars, it just pops into the rubber sleeve installed at the bottle. If the rubber sleeve is dry, applying some silicone lubricant will help. The new windshield washer motor costs from $15 to $30. A repair shop may charge you $50-$150 labor to replace it.

When the switch is operated, there is no voltage at the motor

Windshield washer motor basic wiring diagram
Windshield washer motor basic wiring diagram

If there is no or low voltage, the electric circuit must be checked. The washer motor circuit is very simple: The multifunction switch sends the signal to the body control module or BCM (It could be a different control module, for example, in some Honda cars it's called MICU). The control module supplies the 12 Volt power to the motor.
If there is no power at the motor, is there a 12 Volt power at the connector at the control module? There could be another connector between the windshield washer motor and the control module. Since in many cars, it is located behind the front bumper or in the wheel well, it could be corroded. If there is no power at the control module, does the switch work?
The ground terminal is another important point that must be checked. A loose or corroded ground terminal is one of the most common reasons for some weird electrical problems in any car.
If you need a proper electrical diagram for your car, read more: How to find an owner's or service manual for your car online.

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