5 ways to discover errors in a windshield washer pump

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5 ways to discover errors in a windshield washer pump
5 ways to discover errors in a windshield washer pump

A vehicle's windshield washer pump sprays fluid from a reservoir through the hoses and onto the windshield to clear dirt and dust that could obstruct your vision. The pump pressurizes the liquid so you can spray it. However, this item may work less effectively over time. If the liquid does not come out when you start the pump, it is likely due to several causes, so you should check the pump system to find the source of the problem. The tank may be empty or have a damaged component that you can easily repair yourself. If the pump is not working at all, it is likely to have electrical problems and will need to be replaced entirely.


Method 1 of 5: Diagnose the pump system

Step 1. Listen to the pump as you turn it on to rule out an electrical problem

Turn only the vehicle's battery on and locate the button that activates the pump, which is usually located on the steering column. Press the button and hear a hum from the pump under the hood of the vehicle. If you don't detect a sound, then there is a problem with the fuse, the vehicle's wiring, or the internal electronics of the pump.

  • Open the hood if you have trouble hearing the bomb.
  • If you notice the hum of the pump, but don't see liquid coming out of the nozzles, then the tank is probably empty or has a clog.
  • If the pump is not working at all, you should check its electrical system to see if the pump is malfunctioning.
Troubleshoot a Windshield Washer Pump Step 1
Troubleshoot a Windshield Washer Pump Step 1

Step 2. Check the windshield washer tank to see if it is empty

Open the hood of the vehicle and look for the circular tank cover with a picture of windshield wipers. Unscrew the cap and look inside the tank to check the liquid levels. Usually you will notice a blue or purple liquid inside the tank. If you don't see anything or the levels are near the bottom, then it's time to refill the tank.

  • Shine a flashlight on the tank if you have trouble seeing it.
  • If you detect other contaminants inside the tank, these items can also cause a clog, so you should remove them.


If you are looking to troubleshoot a rear windshield, you will likely find a separate tank in the rear of the vehicle. Consult your service manual if you have trouble locating it.

Troubleshoot a Windshield Washer Pump Step 2
Troubleshoot a Windshield Washer Pump Step 2

Step 3. Look for cracks and leaks in the hoses or tank

Open the hood and prop it up to prevent it from falling. Locate where the hoses connect to the plastic nozzles on the hood and run your fingers along their length. Check the hose for damage or cracks to make sure there are no leaks. You can also check the hoses from the other nozzles. If you find any damage, you must replace the parts.

  • If you have trouble locating the hoses, you can consult the manual or take your vehicle to a mechanic for repair.
  • Replacing your wiper hoses and tanks typically requires parts removal, so it can be difficult to do this at home if you don't have experience working on vehicles.

Method 2 of 5: Fill the Tank

Step 1. Unscrew the cap from the tank

Open the hood so you can access the tank. Locate the tank nozzle, which has a cap with a picture of the windshield wiper on it. Twist the cap counterclockwise to loosen and remove it. Set the lid aside somewhere where it can't get lost.

  • Tank location can vary from vehicle to vehicle, so consult your service manual if you have trouble locating it.
  • Check to see if there is a compartment in or around the trunk if you are refilling a rear windshield tank.
Troubleshoot a Windshield Washer Pump Step 3
Troubleshoot a Windshield Washer Pump Step 3

Step 2. Pour windshield washer fluid up to the tank fill line

Windshield washer fluid is usually a mixture of water and alcohol that cleans dirt and dries quickly. Open the bottle and pour it directly into the tank spout. If you are concerned about spilling the liquid, you can place a funnel in the mouthpiece. Continue pouring the liquid into the tank until it reaches the horizontal fill line on the side.

  • You can buy windshield washer fluid at convenience or automotive supply stores.
  • Windshield washer tanks are generally clear so you can easily see the level of the fluid on the outside.
  • It's okay if you don't fill the tank to the fill line, as the pump will be connected to the bottom.


If you live in an area with freezing temperatures, you should buy washer fluid formulated with a low freezing point. This way it won't harden in the tank or hoses.

Step 3. Seal the tank and close the hood

Replace the cap on the mouthpiece and turn it clockwise until it feels snug. Avoid forcing the lid further. Otherwise, you could damage or break the tank. Lower the hood so the nozzles spray your windshield when you test them.

Never leave the tank uncovered, as the liquid could easily spill or evaporate

Step 4. Test the windshield wiper to see if fluid is coming out

Start the vehicle's battery without starting the engine. Press the button that activates the windshield washer fluid and hold it down for 2-3 seconds. At first, it is normal for fluid to splatter, but it should form a steady stream toward the center of the windshield if the pump is working properly.

If you still don't see liquid coming out of the nozzles, there may be a clog or a problem with the electronics

Method 3 of 5: Unload the obstructions

Step 1. Scrape the dirt off the outer nozzles with a safety pin

Locate 2-3 nozzles along the front of the windshield where fluid is normally sprayed from. Place the tip of a safety pin around the nozzle opening to separate dirt or sticky material. Use a cloth frequently to clean the safety pin. Try to disintegrate as much debris as possible.

  • The nozzles may be connected to the vehicle's windshield wipers.
  • You can re-rinse the dirt in the nozzle after spraying and clogging it. Test the windshield washer pump after clearing the nozzles to see if you fixed the problem.

Step 2. Raise the vehicle on jack stands

Find a sturdy lifting point on the side of the vehicle's chassis to place the jack. Pull down on the jack handle to raise the car off the ground until you have enough room to get under it. Support the chassis with jack stands to prevent the vehicle from falling over. Raise the other side of the vehicle and place 2 more jack stands under the chassis.

Never work under a vehicle while it is on the jack, as it could slide easily

Step 3. Disconnect the hose from the pump to drain the tank

Find the windshield washer pump (which looks like a black cylinder attached to the bottom of the clear tank). Locate the hose that runs from the pump to the vehicle. Place a bucket under the hose and pull it out to drain the tank.

  • You can remove one of the vehicle's wheels if it gets in the way.
  • Try to save the windshield washer fluid if you don't see any dirt or residue. Use a funnel to funnel the liquid into a spare bottle instead of a bucket.

Step 4. Pour clean water through the tank to rinse off dirt and debris

Place an empty bucket under the pump to catch any runoff. Open the hood of the vehicle and unscrew the cap from the tank. Fill a second bucket with lukewarm water and slowly pour it into the washer fluid tank so that it flows through the system. Keep pouring water through the tank until it comes out clean.

Avoid reusing the water you rinse the tank with, as it could reintroduce dirt or debris

Step 5. Unplug the hoses from the nozzles

Locate the L-shaped ends for the nozzles attached to the hoses on the underside of the hood. Squeeze the end of the hose and pull it out of the nozzle to disconnect it. Leave the nozzle on the hood and let the hose hang freely during repairs. Disconnect the hoses from the rest of the nozzles.

You usually don't need tools to disconnect the hoses, but you will likely need a wrench if the clamps secure the hoses to the nozzles

Step 6. Blow compressed air through the hoses and nozzles

Attach the compressed air nozzle to the end of the hose and slide it as far as possible. Press the button down to force air through the hose. If you detect a build-up of dirt inside, it will come out the other side. Spray from each end of the hose to make sure all material is removed. Then it aims the compressed air towards the back of the windshield wiper nozzles and blows air through them as well.

You can buy a can of compressed air at your local hardware store


Avoid applying compressed air from the outer ends of the nozzles, as you could damage the valves that prevent dirt and other materials from entering the hoses.

Step 7. Reconnect the hoses to the pump and nozzles

Press the end of the hose onto the bottom of the hood and the nozzle connection. Slide the hose as far over the nozzle as possible so that it is less likely to leak. Connect the other hoses to the rest of the nozzles. Then, plug the lower end of the hose back into the side of the pump to prevent the tank from leaking any further.

Step 8. Fill the tank to test the windshield wipers

Open the tank and add liquid to the fill line. Close the hood before turning on the battery. Press and hold the windshield button for about 3-4 seconds to allow fluid to begin to flow out of the pump. It's normal for the windshield washer fluid to come out when you first start spraying it, but it should form a steady stream within seconds.

If the windshield wiper still does not work, there is probably a problem with the electrical system

Method 4 of 5: Test the electrical connections

Step 1. Locate the fuse that controls the windshield washer pump

Find the fuse box under the hood near the front fender. Check the fuse diagram on the cover to locate the fuse that controls the windshield washer pump. Remove the cover from the fuse box and find the one that matches.

Consult your service manual if you have trouble locating the fuse box


Typically, the windshield washer pump sits on the same fuse as the motors that control the wiper arm. If they share a fuse and the arms are still moving when you turn them on, then the pump is malfunctioning.

Step 2. Test the fuse with a multimeter for continuity below 1 ohm

Set the multimeter to the lowest ohms (Ω) setting to measure continuity across the fuse. Take the fuse out of the box and place it on a flat surface. Place the first sensor against the left end of the fuse and the second against the other end. Look for a reading of less than 1 on the multimeter to make sure it has continuity.

If you get an "OL" or "OPEN" reading on the multimeter, then the fuse has blown. Take the old fuse to an automotive supply store so you can get a replacement

Step 3. Unplug the connector from the windshield washer pump cable

Keep the vehicle's engine and battery off. Locate the pump at the bottom of the windshield washer tank, which is usually located near the back of the engine well or near the front fender. Look for a wire connector, which looks like a black box attached to the side of the pump with wires leading to the fuse box. Take the base out of the box and pull it out of the pump to disconnect it.

The pump may be easier to access if you raise the vehicle or remove one of the front tires

Step 4. Plug a test light into the connector that leads back to the fuse box

The test lights only come on if the correct voltage is across them. Plug the leads of a 12-volt test light into the connector and push it down as far as you can. Let the light hang close to the pump so you can easily see it while testing the wiring.

You can get test lights at your local hardware store

Step 5. Turn on the vehicle's battery and operate the windshield pump

Turn the key in the ignition to start the battery and keep the engine off. Press and hold the windshield washer button. The blades will not work, but will activate the windshield wiper fuse.

If you have trouble seeing the light while pressing the button, have a helper press it while you are looking at the light

Step 6. Replace the pump if the test light turns on

While holding the button, watch the test light to see if it turns on. If this is the case, the vehicle's wiring will work properly and the problem will reside with the pump. You should take it to a mechanic to have it replaced.

If the light does not come on, there is probably a problem with the switch or wiring. You should consult with a mechanic, as it can be very difficult to repair the car's electrical system on your own

Method 5 of 5: Relocate the nozzle

Step 1. Attach a safety pin to the hole in the mouthpiece

Choose a safety pin or a tool that is narrow enough to fit in the outer hole of the nozzle. Push the safety pin 1 cm (½ inch) into the hole so you can more easily control the nozzle.

You will likely find a special tool designed to attach your windshield nozzles. You can get them for about $ 5 at an auto supply store

Step 2. Move the safety pin to point the nozzle toward the center of the windshield

Move the safety pin up, down, left or right to adjust the spray direction of the nozzle. Try to move the nozzle so that the stream falls in the center of the windshield and the windshield wipers distribute the fluid evenly.

  • You should only make small adjustments to the direction of the nozzle, as it may spray more than expected.
  • Don't try to force the mouthpiece to move if it resists. Otherwise, you could break it.

Step 3. Test the windshield wiper to make sure the fluid is evenly distributed

Turn on the vehicle's battery and press the windshield wiper button. Hold down the button until the fluid sprays onto the windshield. If it doesn't land in the center of the windshield, make a mental note of how far you need to move it so you can adjust from there.

If the nozzle sprays too high or low, the fluid can bypass the windshield entirely


Consult your service manual if you have trouble locating parts, as their location may vary by make and model


  • If you have trouble detecting the problem or repairing the pump, you can take the vehicle to a mechanic.
  • Keep the vehicle battery off while handling electrical components and cables to avoid electrocution.

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