How to Test a Power Window Switchby Elyse James
It's a hot summer day and you go to roll down your window using the power window switch, but instead of delivering a refreshing breeze, the window doesn't budge. If you are stuck with this unfortunate situation, or if your window is malfunctioning in other ways, you could have a problem with your window switch. To test the window switch you will need to use a voltmeter and ohmmeter.
Remove the faulty window switch from the door. To do this, you must press on the four tabs on the switch to release the switch. A small flat tip screwdriver can come in handy during this process.
Turn the switch to the "open" position.
Attach the voltmeter to the switch plug and test to see if there are 12 volts coming from terminal 4 to the ground and from terminal 5 to the ground. If the voltage is the correct number, this tells you that the power and wiring leading the window switch is sufficient.
Set the switch to the "open" position. Attach the ohmmeter to the varying terminal combinations. There should be low resistance coming from terminals 1 to 4 and from 2 to 3.
Set the switch to the "close" position. Attach the ohmmeter to the varying terminal combinations. There should be a low resistance from terminals 1 to 3 and from 2 to 5.
Determine whether the switch is faulty based on the combined readings from the ohmmeter and the voltmeter.