Most automotive power window failures are due to a failed window switch. However, fuses, wires and electric motors may fail too. The next steps require a little knowledge of electrical circuit operation, but if you want to learn basic troubleshooting procedures, these steps should work for most car models. If you need specific information about your particular vehicle, consult your vehicle service manual.
Park your car in a safe place. If your power windows only operate with the ignition switch on, make sure to leave it on. Also, if the driver’s window panel has a lock control switch, make sure it is in the “On” position to allow the use of individual window switches.
Check the main power window fuse or breaker if none of the windows in the vehicle works. In most models, the fuse box is located under the dashboard, on the driver’s side. If the fuse is blown, replace it and check to see if the windows will operate.
Check the wires between the master control switch and the fuse box using a test light. On most vehicles, you can pull the control switch off the panel using a screwdriver. Clip the end of the test light wire to a good ground. Turn on the ignition switch and with the tip of the test light, touch the wires connected to the control switch. If the test light does not come on, voltage is not reaching the switch. Most likely, your problem is at the wire coming from the fuse box, the wire feeding power to the power window switch or wire connections.
Check the switch at the inoperative window if only that window is not working. In most vehicle models, you can pull the switch using a screwdriver. Clip the end of the test light to a ground and touch both ends of the switch electrical connectors as you operate the switch. If the test light does not come on, check for an opening at the wire coming from the main control switch. If the test light only comes on at one side of the switch, the switch is defective and should be replaced. If the light comes on at both sides of the switch, go on to the next step.
Remove the door panel so you can reach the power window motor. At the window motor electrical connector, touch the wire coming from the switch with the test light as you operate the switch. If the light does not come on, there is a short at the wire. If the light comes on, make sure the wire connection is good and there is not a mechanical obstruction preventing the window from operating.
Unplug the electrical connector from the power window motor. Place a car battery next to the window you are testing and connect two jumper wires between the battery and the motor electrical connector. If the motor still does not operate, replace the motor. If the motor works, there is a failed connection at the switch side of the electrical connector.