How to Test Windshield Washer Pump: A Comprehensive Guide

The windshield washer pump is a crucial component of your vehicle’s washer system. It ensures a steady flow of washer fluid from the reservoir to the windshield, helping you maintain visibility during inclement weather or when your windshield gets dirty. When the washer pump malfunctions, it can severely impact your ability to keep the windshield clean, especially in conditions like rain, snow, or dust storms. Knowing how to test your windshield washer pump is essential for troubleshooting the system before deciding on repair or replacement.

In this blog post, we’ll walk through a detailed process for testing a windshield washer pump. We will also cover some common issues associated with the washer pump, tools you will need, and how to troubleshoot other components of the washer system.

How to Test Windshield Washer Pump

Before starting the test, gather the following tools and equipment:

• Multimeter: To check the electrical continuity and voltage.
• 12V test light: For testing power at the pump.
• Screwdriver set: To remove panels or components.
• Bucket or catch pan: To capture any washer fluid.
• Needle-nose pliers: Useful for gripping connectors and hoses.
• Jack and jack stands: If the pump is located under the vehicle.
• Owner’s Manual: For specific details on the washer pump’s location.

Step-by-Step Guide to Testing the Windshield Washer Pump

Here’s a step-by-step guide to testing your windshield washer pump:

Step 1: Locate the Windshield Washer Pump

The first step is to locate the washer pump, which is typically mounted on or inside the washer fluid reservoir. The reservoir is usually found under the hood of the car, but it can vary based on the make and model of your vehicle. If you cannot locate the pump, refer to your vehicle’s owner’s manual or a service manual for your specific model.

Step 2: Check the Washer Fluid Level

Before assuming the pump is the problem, make sure there is sufficient washer fluid in the reservoir. Sometimes, a simple lack of fluid can cause the washer system to malfunction. If the fluid level is low, fill the reservoir and test the system again by activating the washer from inside the car. If the washer still doesn’t work, proceed to the next steps.

Step 3: Inspect for Visible Damage

Conduct a quick visual inspection of the washer system. Check for cracked or disconnected hoses, leaks, or physical damage to the washer pump. Look for loose electrical connections and examine the pump itself for cracks or signs of wear. Any damaged or disconnected parts should be repaired before testing the pump.

Step 4: Test the Windshield Washer Pump Voltage

Testing the voltage at the pump will help you determine whether the pump is receiving power. Follow these steps:

1. Access the pump wiring harness by unplugging the electrical connector from the pump.
2. Turn the ignition to the ‘ON’ position, but do not start the engine.
3. Use a multimeter or a 12V test light to check for voltage at the connector. Set the multimeter to the DC voltage setting. Place the red probe on the positive terminal and the black probe on the negative terminal of the connector.
4. Activate the windshield washer switch inside the car to trigger the pump. You should see a reading of around 12 volts on the multimeter or the test light should illuminate.

• If there is voltage present: The wiring and the switch are functioning correctly, and the problem likely lies within the washer pump itself.
• If there is no voltage: The issue could be with the wiring, the fuse, or the switch, and you should check these components.

Step 5: Check the Windshield Washer Pump Fuse

If you didn’t detect voltage at the pump, the next step is to check the fuse that controls the washer pump circuit.

1. Locate the fuse box, which is typically under the dashboard or in the engine compartment.
2. Refer to the fuse box diagram (usually on the cover or in the owner’s manual) to find the fuse for the windshield washer pump.
3. Remove the fuse and inspect it. If the fuse is blown, replace it with a new one of the same amperage rating.
4. Test the washer system again. If the fuse blows immediately after replacement, there might be a short circuit in the wiring.

Step 6: Perform a Continuity Test on the Washer Pump

If there is power to the pump but it still doesn’t work, the pump motor may have failed. Use a multimeter to check for continuity within the pump:

1. Set the multimeter to the resistance (ohms) setting.
2. Disconnect the wiring harness from the washer pump.
3. Touch the multimeter leads to the pump terminals. A reading of infinite resistance (or “OL” on some multimeters) indicates an open circuit, meaning the motor is defective and needs to be replaced.

Step 7: Directly Power the Pump

To rule out any other issues and confirm that the pump motor itself is faulty, you can apply power directly to the pump using a 12-volt source (like your car’s battery). Here’s how:

1. Disconnect the pump’s electrical connector.
2. Take two wires (one positive and one negative), and connect them to the corresponding terminals of the pump.
3. Touch the other ends of the wires to your car battery’s positive and negative terminals.
   • If the pump operates when directly powered, the issue is with the wiring or the control switch.
   • If the pump does not operate, it’s likely faulty and will need to be replaced.

Step 8: Replace the Windshield Washer Pump (If Necessary)

If the pump fails the voltage or continuity test and does not respond when powered directly, it is likely defective. You can purchase a replacement pump, usually available at auto parts stores or online. Follow these steps to replace the windshield washer pump:

1. Drain the washer fluid from the reservoir into a bucket.
2. Disconnect the electrical connector and fluid hoses from the pump.
3. Remove the pump from the reservoir (this may require unscrewing or unclipping).
4. Install the new pump by reversing the removal process.
5. Reconnect the hoses and the electrical connector.
6. Refill the washer fluid reservoir and test the system again.

Common Windshield Washer Pump Issues

Common windshield washer pump issues include:

• No Washer Fluid Sprays: If the washer system is running but no fluid comes out, it may be due to a clogged nozzle, kinked hose, or an empty reservoir.
• Intermittent Operation: If the washer pump works only sometimes, it could be due to loose connections or a failing pump motor.
• Weak Spray: A weak spray is often caused by partially clogged nozzles, low washer fluid levels, or a failing pump.

Frequently Asked Questions

Here are some FAQs about testing windshield washer pump –

1. How often should I check my windshield washer pump?

It’s a good idea to check the windshield washer pump during regular maintenance, such as every time you change the oil or top up fluids. If you notice any issues with the spray pattern or functionality, test the pump immediately.

2. Can a faulty windshield washer pump drain my car battery?

While it’s uncommon, a faulty washer pump could short-circuit and cause excessive electrical draw, which might drain your battery over time. If the pump is malfunctioning, it’s best to address the issue as soon as possible.

3. Why is my windshield washer pump making noise but not spraying fluid?

If the pump makes noise but does not spray, the issue may be a clog in the hose or nozzle, an empty fluid reservoir, or a weak pump. Check for blockages and make sure the reservoir is full.

4. How much does it cost to replace a windshield washer pump?

The cost to replace a windshield washer pump typically ranges from $50 to $150, depending on your vehicle’s make and model. Labor costs can add another $50 to $100 if you have the replacement done by a professional.

5. Is it difficult to replace a windshield washer pump?

Replacing a windshield washer pump is generally a straightforward task that most people can complete with basic tools. However, accessing the pump can be tricky on some vehicles, especially if it’s located under the reservoir or near other components.

Testing and troubleshooting your windshield washer pump is an important skill that can save you time and money on repairs. By following this guide, you can quickly determine whether your pump is faulty or if the issue lies elsewhere in the system, ensuring your windshield washer is always in top condition.

Conclusion

Testing your windshield washer pump is an essential step in diagnosing and addressing issues that affect your vehicle’s visibility, especially in adverse conditions. Regular maintenance and inspections of the washer system can prevent minor issues from escalating into bigger problems.

Whether it’s a simple fix like unclogging a nozzle or replacing the pump entirely, understanding how to test the windshield washer pump empowers you to keep your car safe and functional. If you encounter difficulties, don’t hesitate to consult a professional mechanic for assistance.