Windshield Washer Pump

In modern cars, the windshield washer pump comes as one unit with a small electric motor. Typically, the windshield washer pump is installed in the lower portion of the windshield washer fluid tank (bottle). 

Windshield washer pump (motor), located at the bottom of the windshield washer fluid tank.

In most cars, the windshield washer tank is located behind the front bumper, in front of one of the front wheels.

How It Works: 
When you operate the washer with the switch, it sends the signal to the control module (e.g. BCM) that, through the relay, operates the windshield washer pump. The pump pumps the windshield washer fluid through the hoses that are connected to the washer jets.

Windshield washer pump/motor basic wiring diagram

Windshield washer pump problems

One of the common problems is when the windshield washer pump electric motor fails. In some cases, the pump fails, so you can hear the motor running when the washer switch is operated, but the washer fluid doesn't spray. A bad windshield washer pump (motor) must be replaced.

There are several other problems that can also cause the windshield washers not to work. For example, corrosion at the washer pump electrical connector or problems with the electrical circuit can also cause the pump not to work. Not all problems with the windshield washers are caused by issues with the washer pump. For example, a leaking or pinched fluid hose can also cause the washers not to work even when the washer pump is running. The symptom of a disconnected hose is the washer fluid leaking somewhere under the car when the washer pump is operated. Due to its location, the washer fluid tank is also prone to damage or cracks that can cause the fluid to leak out. 

 

Windshield Washer Pump Replacement
Replacing the windshield washer pump (motor) is not very difficult if there is good access to its location. In most cars, it just pops into the rubber sleeve installed at the bottle. 

Windshield water fluid pump

Testing The Windshield Washer Pump
When you press the washer switch, the pump (motor) is powered by the 12 Volt battery power. It only works when the ignition is ON or when the engine is running. If you don't hear the washer pump running when operating the washer switch, the first step is to check the fuse. You can find the location of the fuse on the fuse box cover or in the owner's manual.

A fuse box

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. If the fuse is OK, the voltage at the motor needs to be checked. 

There could also 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 is prone to corrosion damage. 

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 many hard-to-diagnose electrical problems.

How To Measure The Voltage
if there is 12V at the connector and the connector is not corroded and the motor doesn't run, the motor is bad.

A multimeter

Typically, the voltage at the pump is measured while the connector is still connected to the pump (motor) when the switch is activated. If there is 12 Volt at the pump (motor) connector but the pump doesn't run, the pump (motor) itself is bad and must be replaced. The connector also must be checked for corrosion.

It is important to check the voltage with the connector still connected. This way, if one of the wires is 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 circuit.

If there is no or low voltage at the pump when the switch is activated, the electric circuit must be checked. The washer pump (motor) circuit is simple: The multifunction switch sends the signal to the body control module or control module. The control module supplies the 12 Volt power to the relay or directly to the pump (motor). If there is no power at the motor, the voltage must be checked at the connector at the control module.

If all of this sounds complex (and it should), it is best then to take it to your technician to prevent any "further problems aka. burn the brain box (control module)".

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Email; vverteautosevcs@gmail.com
Phone; 09137103730

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