Power window system – general information

1. The power window system controls the electric motors, mounted inside the doors, that lower and raise the windows. The power win­dow system consists of the control switches, the fuse, the circuit breaker, the motors, the window regulators (the scissors-like mecha­nisms that raise and lower the window glass) and the wiring connecting the switches to the motors. When the ignition switch is turned to ON, current flows through the power window fuse in the engine compartment fuse and relay box to a circuit breaker located in the instrument panel wiring harness (located near the parking brake pedal). From there, current flows to the power window switches.

2. The power windows are wired so that they can be lowered and raised from the mas­ter control switch by the driver or by passen­gers using remote switches located at each passenger window. Each window has a separate motor that is reversible. The position of the control switch determines the polarity and therefore the direction of operation.

3. The power window system will only operate when the ignition switch is turned to ON. In addition, a window lockout switch at the master control switch can, when activated, disable the power window switches on the other doors. Always check these items before troubleshooting a window problem.

4. These procedures are general in nature, so if you can’t find the problem using them, take the vehicle to a dealer service depart­ment.

5. If the power windows don’t work at all, check the fuse or circuit breaker.

6. If only the rear windows are inoperative, or if the windows only operate from the mas­ter control switch, check the window lockout switch for continuity in the unlocked position. If it doesn’t have continuity, replace it.

7. Check the wiring between the switches and the fuse for continuity. Repair the wiring, if necessary.

8. If only one window is inoperative from the master control switch, try the control switch at the window that doesn’t work. Note: This doesn’t apply to the driver’s door window.

9. If the same window works from one switch, but not the other, check the switch for continuity.

10. If the switch tests OK, check for a short or open in the wiring between the affected switch and the window motor.

11. If one window is inoperative from both switches, remove the trim panel from the affected door (see Body), then check for voltage at the switch and at the motor while operating the switch. First check for voltage at the electrical connectors for the circuit. With the ignition key turned to ON and the connectors all connected, backprobe at the designated wire (see the wiring diagrams at the end of this Chapter) with a grounded test light. Pushing the driver’s window switch to the DOWN position, there should be voltage at one terminal. Pushing the same switch to the UP position, there should be voltage at another terminal. If these voltage checks are OK, disconnect the electrical connector at the driver’s motor, and check it for voltage when the switch is operated.

12. If voltage is reaching the motor and the switch is OK, disconnect the door glass from its regulator (see Body). Move the win­dow up and down by hand while checking for binding and damage. Also check for binding and damage to the regulator. If the regula­tor is not damaged and the window moves up and down smoothly, replace the motor. If there’s binding or damage, lubricate, repair or replace parts, as necessary.

13. If voltage isn’t reaching the motor, check the wiring in the circuit for continuity between the switches and motors (see the wiring dia­gram at the end of this Chapter).

14. If you have to replace the main power window switch, pry it out of the door trim panel, then disconnect the electrical connector (s) from the switch.

15. When you’re done, test the windows to confirm that the window system is functioning correctly.