Reasons for the Windshield Washers not Working

Can't fix your car problem on your own? Ask a live mechanic!

I wanted to write an article addressing common reasons for the windshield washers not working properly. After exhaustive research it seems as if this common problem is somewhat model specific. If you have an old Toyota Corolla you might experience a crack in the fluid reservoir. On General Motors cars and trucks from the late 90s they used a cheap washer pump that often fails. Therefore, in this article we’ll empower you to diagnose and fix several issues that stop the windshield washers from working properly.

Improper Windshield Washer Operation

Windshield Washer Nozzles
Windshield Washer Nozzles

Before we dive into the individual diagnosis and repair of specific problems let’s talk a little bit about the symptoms that accompany a windshield washer malfunction. Of course, you have the scenario where you hit the washer button and no fluid comes out. However, when this happens there’s an important thing to know about the problem.

Do you hear the windshield washer pump running is the question that needs answering? The pump can run and not pump fluid for several reasons. If you can’t hear the pump run have an assistant hit the washer button while you put your ear close to the windshield washer reservoir. This is where you’ll find the pump in many applications.

Here’s the important part of this test. If the pump runs we don’t have to perform any diagnosis to the electrical side of the circuit. This means no testing of the switch, the relay and all the wiring that attaches these devices to the washer pump.

In another common scenario the washer runs, but the fluid doesn’t discharge with enough force to reach the windshield’s line of sight. This situation also allows us to bypass diagnosis of the complex electrical system that sends power to the pump. Now we can concentrate on the pressure produced by the pump and the ability of the lines and the windshield washer nozzle to spray properly.

My Windshield Washers are not Working

Universal Windshield Washer Tank
Universal Windshield Washer Tank

Customers often come in and say their windshield washers aren’t working. I wish this wasn’t true, but most of the times when I pop the hood and check the reservoir level, I find an empty container. In a situation where they mount the pump in the reservoir, the washer fluid actually cools and lubricates the pump impeller.

When a driver with an empty reservoir continues to operate the windshield washer button, they can ruin the delicate impeller inside the windshield washer pump. So in this situation, when I fill the reservoir, it might also become necessary to replace the pump. Car owners depend on the auto repair center to refill all of their fluids during an oil change service. However, this doesn’t always happen.

Maybe it’s an accident and they just forgot to refill the washer fluid? It’s also a way to save money on expenses for performing a service that shows very little profit for the shop. In either situation, the vehicle owner must take responsibility. Open the hood after service and make sure you got what you paid for. You need to take charge of your own automotive maintenance. We don’t want to be out on the highway and hit the washer button, after going through a mud puddle and find out the well is dry.

Diagnosing Windshield Washer Problems

Windshield Washer Special Hose
Windshield Washer Special Hose

When you hear the windshield washer pump running and you see a full reservoir, two possible outcomes exist. The first problem is a restriction in the network of washer hoses that run from the pump outlet to the windshield washer nozzles.

They use specialized hoses in the Windshield washer system. You can’t use standard vacuum line to replace automotive washer hoses. These thin walled tubes look more like straws than vacuum lines. They join these hoses with plastic connectors throughout the engine compartment.

Windshield Washer Nozle
Windshield Washer Nozzle

You simply disconnect the hose and run the pump and see if fluid pumps out to distinguish cleared sections of line. With that said, when mechanics find a clog in the windshield washer system it’s often closer to the windshield washer nozzles.

Also note that the windshield washer nozzles themselves remain a possible source of the clog. You can replace these washer jets and sometimes you can use a very thin piece of mechanic wire to clean them out. However, make sure not to enlarge the plastic hole in the nozzle. This changes the spray pattern as it hits the windshield.

Diagnosing Defective Windshield Washer Pumps

Windshield Washer Pump
Windshield Washer Pump

Windshield washer pumps can fail in several different ways. Picking up from where we left off in the last section let’s say you hear the pump running, but no fluid shoots out. If you disconnect the washer fluid lines and they aren’t clogged, you might have a pump pressure problem.

Mechanics check two important areas on a windshield washer pump. These of course are the pump inlet and outlet locations. Some manufacturers place a filter on the inlet side to stop debris from working its way up to the windshield washer nozzles. If the factory equipped your vehicle with one of these, it needs cleaning and checking. If the inlet side tests good, then you’ll need to focus on the outlet side of the windshield washer pump.

As mentioned above, there’s a small, delicate impeller that pressurizes the windshield washer fluid. Even if you don’t run the windshield washer reservoir dry, some manufacturers experience windshield washer pump failure at a high rate. The Chevy Silverado pickup trucks from the late 90s make this list.

You can put more than 300,000 miles on the engine in these trucks. Unfortunately, the windshield washer pump won’t go that far. If you disconnect the outlet hose from the windshield washer system and operate the switch you should see a pressure discharged stream with about 6 psi of force. If it just trickles out, it’s time to try replacing the washer pump itself. Replacing the pump isn’t too difficult and if you need further assistance, please consult your model specific auto repair manual.


Can't fix your car problem on your own? Ask a live mechanic!