GM Service Manual Online
For 1990-2009 cars only

A permanent magnet motor operates each of the power side windows. Each motor raises or lowers the glass when the motor receives voltage. Each direction the motor turns depends on the polarity of the supply voltage. The window switches control the polarity of the supply voltage.

The left front door lock and side window switch controls all of the motors. The other window switches control only the window regulator motor in that door.

A built-in circuit breaker protects each motor. The circuit breaker opens the circuit when the switch is open for too long of a period of time under the following conditions:

    • The window has an obstruction.
    • The window is fully open or fully closed.

The circuit breaker resets automatically as the circuit breaker cools.

Master Window Switch Operation

When the ignition switch is in the RUN  position, battery voltage is available through the PWR WDO circuit breaker. The switch supplies battery voltage to the window regulator motor. The power window motor grounds the window switch down contact.

The regulator motor runs in order to drive the window upward. The operation of the down switch supplies battery voltage in the opposite direction to the window regulator motor through window regulator grounds window switch up contact. The motor runs in order to drive the window downward.

Individual Window Switch Operation

When the ignition switch is in the RUN position, battery voltage is available to the window switch through the PWR WDO circuit breaker. The operation of the right side up switch supplies battery voltage to the right front window regulator motor.