GM Service Manual Online
For 1990-2009 cars only

Power Windows System Components

The power window system consists of the following components:

    • Driver window switch
    • Passenger window switch
    • LR window switch
    • RR window switch
    • Window motors in each of the doors
    • PWR/WINDOW 30A Fuse

Power Windows System Controls

The power windows system can be controlled by pressing or pulling the appropriate power window switch.

Driver 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.

Express Down Feature

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.

Lockout Switch Feature

The driver 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 driver power window switch.

Passenger Window Operation

Battery voltage is supplied to the front passenger power window switch through the accessory voltage supply circuit. Ground for the passenger power window motor is supplied through normally closed up and down contacts of both the front passenger power window switch and the driver 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 front passenger power window motor. Since the other side of the front passenger power motor is connected to ground through the normally closed up contacts of both the front passenger and driver power window switches, 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.

The front passenger power window can also be controlled from the driver power window switch.

Rear Passenger 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 driver 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 driver 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 driver power window switch.