Troubleshooting Automobile Power Windows

It can often be difficult to troubleshoot your automobile's power windows because there are many parts that can cause them to fail. There are different places to look for a malfunction, depending on how many of your car's power windows are still working and whether or not they are getting power to the window switch.

Troubleshooting automobile power windows: Only one window is failing

If only one power window is failing, it is likely that it is only the window switch or lifting mechanism located in that door that is causing the problem. Even if the window switch and lifting mechanism in the door is not malfunctioning, there can be wires or connections that have been knocked loose while the car was in motion. Depending on the type of car you drive, it can be easy or quite difficult to remove the interior door panel to check or replace these parts. Once you get the door panel removed, the wiring for the power window switches are generally held within a rubber or plastic tube that must be cut in order to check the wires.

Troubleshooting automobile power windows: All windows are failing

When none of the power windows on an automobile are working, it is probably an electrical problem somewhere in the car. The easiest place to check is the fuses and circuit breakers to make sure it is not a simple fix. If these check out, the next place to look is the electrical relay in the car's instrument panel. This relay is the piece responsible for distributing power to each of the individual window switches. Your mechanic or local auto parts store will usually test the circuit for free or at a nominal charge.

Troubleshooting automobile power windows: Testing the master window switch

The car's master window switch is another area that can malfunction and cause all of the vehicle's power windows to go out at once. To troubleshoot this part of your car's electrical system, you will need a copy of the master wiring diagram to know exactly which wires control the master window switch. Looking on the wiring diagram, trace the wire that runs from the instrument panel's relay all the way down to the master power window switch. Using a test kit, check the current as you make your way down this wire. If you get all the way to the master power window switch without finding a problem, check each switch individually by pressing it up and down while testing the connecting wire for electrical current. If you are getting current into the power window switch, but none is coming back out when you toggle it, the master window switch is defective.