Troubleshooting a Faulty Power Window Switch

  • 2-6 hours
  • Intermediate
  • 1-200

The power window switch is one of the many conveniences in a car that we take for granted. It raises and lowers the window without much thought. Many windows today have this convenience. The driver has the luxury of operating all the windows from this position, and can even lock them if he chooses. This system is comprised of different circuits, relays, and fuse for each of the individual windows. When there is a problem with the power window switch, there are several things to look at. Here are some things to look out for to help diagnose the problem in your power windows.

Check Main Fuse Box

Place your key into the ignition and turn it to "On". You do not have to actually start the car to operate the windows. Once the car in "On", then try working the different windows. If none of them are working, then you may have a simple problem with the main fuse. Locate the fuse box and check the fuse on it. If it is blown you will notice a break in the metal filament. Replace the fuse and check the windows again.

No Power to Switch

To find out where the problem is you will need to have a test light. Check the main circuit relay with the test light to see if there is any voltage coming from it. If there is, then there is a short in the wire coming from the main wire that is supplying the switches. If there is no voltage being shown on the test light, check the main wire to see if there is voltage coming to the relay switch. If so, then replace the wire. If not, then the problem is with a short in the wire from the fuse to the relay.

Humming, but Window Doesn't Work

When you press the power window switch and you hear a humming sound, but the window is not working, then you will have a problem with motor or gears. You will need to remove the door panel in order to check to see which one is not working. Use a test light on the motor to check for any power, and inspect the window gears for any signs of broken teeth.

Check Lock Switch

With the key turned to the "on" position on the ignition switch, you can check the window lock switch with a multimeter. If there is no power, or continuity, with this switch you should replace it. This lock switch can malfunction and cause both of the rear windows to not open. Replace this switch is an easy process involving a few basic tools.

Worn Out Regulator

For some troubleshooting purposes you will need to remove the door panel. Once you have removed the screws around the door, you can pop the rivets that are holding it on. Look at the regulator that holds the window to the frame. If it is worn out it will not work the way that it should and raise, or lower, the window. Replace this regulator and you will notice a big difference in the way the switch operates.