Power Windows Description and Operation

Power Windows Description and Operation

Power Window System Components

The power window system consists of the following components:

* LF power window master switch
* RF power window switch
* Reversible power window motors in each of the doors (circuit breaker protected)
* DRLK/WDO circuit breaker 30A

Power Window System Controls

The power window system will operate anytime the ignition switch is in the ACCY or ON position.

The LF power window master switch can control the up and down functions of both the windows in the vehicle. The passenger door power window switch can only control the up and down functions of the passenger window.

Power Window Motor Operation

A permanent magnet motor operates each of the power side windows. Each motor raises or lowers the glass when the motor receives voltage. The direction the motor turns depends on the polarity of the supply voltage. The power window switches control the polarity of the supply voltage. A built-in circuit breaker protects each motor. The circuit breaker opens when the switch is depressed for a extended period of time under the following conditions:

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

The circuit breaker will reset automatically as the circuit breaker cools.

Power Window Operation

The power window system is supplied voltage through the power window relay. The supply side of the relay is connected to DRLK/WDO or the DRLK circuit breaker through the battery positive voltage circuit. The relay coil is connected to a constant ground source and is controlled through the ignition 3 voltage circuit from the B/U & IGN3 circuit breaker. When the ignition is placed in the ON position the relay is energized and voltage is available at both power window switches through the ignition 3 voltage circuit.

The normally closed contacts of the switch are connected to ground and the center pole is connected to the accessory voltage circuit. By placing the left power window switch in the down position, voltage is applied to the power window motor left front down circuit and to the power window motor. The other side of the power window motor is connected to ground through the normally closed contacts of the left power window switch through the power window motor left front up circuit and drives the window down.

By placing the power window switch in the up position the polarity of the motor is reversed and the motor drives the window up.