GM Service Manual Online
For 1990-2009 cars only

Power Windows System Components

The power window system consists of the following components:

    • Driver power window switch--Controls the up and down operation of the driver and LR passenger power windows
    • Front passenger power window switch--Controls the up and down operation of the front passenger and RR passenger power window
    • LR power window switch--Controls the up and down operation of the LR power window
    • RR power window switch--Controls the up and down operation of the RR power window
    • Window lockout switch--Part of the driver power window switch and enables or disables rear power window operation from the rear window switches
    • Power window motors in each of the doors
    • WDO/SUNROOF/AIR 30A circuit breaker--Located in the underhood fuse block and provides voltage to the power window relay, air pump relay and sunroof system at all times
    • Power window relay--Located in the right instrument panel (I/P) fuse block and provides voltage to the power window switches when the ignition is in ACC or RUN

Power Window System Controls

The power window system will operate any time the ignition is the ACC or RUN position. The power window switches located in the console contain individual window switches for each of power windows. All windows may be controlled up and down from the console power window switches. The individual rear passenger power window switches will only control the up and down operation of their respective power window.

Power Window Motor Operation

Each power window contains a reversible power window motor. The direction the window travels is dependent upon the polarity of the supply voltage. By reversing polarity of the supply voltage the window motor will move up or down. Each power window motor is internally circuit breaker protected.

Driver Power Window Operation

Battery voltage is supplied to the driver power window switch through the accessory voltage supply circuit. The driver power window switch also receives a constant ground source. The power window motor control circuits are connected to ground through the normally closed up and down contacts of the driver power window switch. When the driver power switch is placed in the down position, the power window motor down control circuit is switched to 12 volts and is applied to the down side of the driver power window motor. Since the other side of the driver power motor is connected to ground through the normally closed contacts of the up switch, the driver window travels down. By placing the driver power window switch in the up position, the polarity of the driver power window motor is reversed and the window travels up.

Driver Power Window Express Down Operation

If the driver power window switch is pressed momentarily in the down position past the first detent, the window will travel to the full open position unsupervised. To cancel to express down operation, momentarily press the driver power window up switch.

Front Passenger Power Window Operation

Battery voltage is supplied to the front passenger power window switch through the accessory voltage supply circuit. The passenger window switch also receives a constant ground source. The power window motor control circuits are connected to ground through the normally closed up and down contacts of the front passenger power window switch. When the front passenger power window switch is placed in the down position, the power window motor down control circuit is switched to 12 volts and is applied to the down side of the power window motor. Since the other side of the power motor is connected to ground through the normally closed contacts of the up switch, the window travels down. By placing the front passenger power window switch in the up position, the polarity of the power window motor is reversed and the window travels up.

Rear Passenger Power Window Operation

The rear passenger power window switches receive battery voltage through the window lockout control circuit if the window lockout function is disabled. Ground for the rear passenger power window motors is supplied through normally closed up and down contacts of both the rear passenger power window switches and the console power window switch. When the either rear passenger power window switch is placed in the down position, the power window motor down control circuit is switched to 12 volts and is applied to the down side of the rear passenger power window motor. Since the other side of the rear passenger power motor is connected to ground through the normally closed up contacts of both the rear passenger and console power window switches, the window travels down. By placing the rear passenger power window switch in the up position, the polarity of the power window motor is reversed and the window travels up.

The rear passenger power windows can also be controlled from the console power window switches.

Power Window Lockout Operation

The console power window switch contains a window lockout switch. The window lockout switch completes or interrupts the window lockout control circuit. If the window lockout switch is enabled, there is no voltage available at the rear power window switches and rear power window will not operate from the rear power window switches. The rear power windows will operate from the console power window switches.