GM Service Manual Online
For 1990-2009 cars only

Power Windows System Components

The power window system consists of the following components:

    • Master window switch
    • LR power window switch
    • RR power window switch
    • Power window motors in each of the doors
    • 25A power window circuit breaker

Front Window Operation

When the ignition switch is in the RUN position and the driver window switch on the master window switch assembly is pressed to the down position, voltage is applied to the window motor causing the driver window to open. When the driver window switch is pressed to the up position, voltage is applied to the window motor in the opposite direction. The driver window closes. The return path to ground is supplied through the inactive control circuit being normally grounded through the master window switch. The front passenger window operation is identical to the driver window operation.

The master window switch also controls the LR, and RR windows. Refer to rear window operation below for details on how these windows operate.

Express Down Feature

The driver window will travel to the fully down position when the driver window switch on the master window switch assembly is momentarily pressed down past the first detent. Press the driver window switch to the up position in order to stop the window.

Lockout Switch Feature

The master window switch has a lockout switch which allows the customer to stop the rear windows from operating from the individual window switches.

Rear Window Operation

When the ignition switch is in the RUN position, the lockout switch is disengaged (up) and the individual window switch is pressed to the down position, voltage is applied to the window motor down control circuit, causing that window to open. When the individual window switch is pressed to the up position, voltage is applied to the window motor up control circuit, and that window closes. The return path to ground is supplied through the inactive control circuit being normally grounded through the master window switch. Operation is the same from the master window switch, except that the lockout switch position is ignored.