GM Service Manual Online
For 1990-2009 cars only

General Window Circuit Description

A permanent motor operates each of the power windows. Each motor raises or lowers the glass when voltage is supplied to the motor. The direction that the motor turns depends on the polarity of the supply voltage that the switch provides.

The LH front power window master switch controls all of the window motors. The passenger window also has a separate switch (although it is enabled through the LH window switch).

Each motor is protected by a built-in circuit breaker. The circuit breaker opens the circuit if the window switch is held down too long and the following conditions apply:

    • The window is obstructed
    • The window is full up
    • The window is fully down

The circuit breaker automatically resets while cooling.

When the ignition switch is turned to the RUN position, CKT 343 (YEL) supplies battery voltage to the LH front power window master switch.

When you operate any of the UP switches, battery voltage is supplied to the window motor. the voltage is grounded through the DN contact. The motor runs in order to drive the window up. When you operate any of the DN switches, battery voltage is supplied to the window motor in the opposite direction. The window motor is grounded through the UP contact. The motor runs in order to drive the window down.

LH Front Power Window Master Switch Circuit Description

When the ignition switch is in the RUN position, battery voltage applies to the window switch. The voltage applies through the WINDOWS circuit breaker and CKT 343 (YEL). When the left hand (LH) UP position is pressed, the window switch the battery voltage applies to the LH window motor. The voltage applies through CKT 164 (DK BLU). The motor grounds through CKT 165 (BRN) DN contact in the window switch. The motor runs to drive the window up. When the LH DN position in the window switch is pressed, the battery voltage applies to the window motor. The voltage applies in the opposite direction through CKT 165 (BRN). The window motor grounds through the following components:

    • CKT 164 (DK BLU)
    • The UP contact in the front power window master switch.

The motor runs to drive the window down.

When the right hand (RH) UP position in the window switch is pressed, the battery voltage applies to the RH window motor. The voltage applies through the following pattern:

  1. CKT 166 (DK BLU)
  2. To the UP contact in the passenger window switch.
  3. Through the window motor

The motor grounds through the following pattern:

  1. Through CKT 667 (BRN)
  2. To the DN contact in the passenger
  3. Through CKT 167 (TAN)
  4. To CKT 750 (BLK)
  5. To ground G110

When the RH DN position in the window switch is pressed, the battery voltage applies to the RH windows in the opposite direction through CKT 167 (TAN). The voltage also applies in the DN contact in the passenger window switch through CKT 667 (BRN) to the window motor. The motor grounds through the following pattern:

  1. Through CKT 666 (DK BLU)
  2. To the UP contact in the passenger window switch
  3. Through CKT 166 (LT BLU)
  4. Through the UP contact in the driver window switch
  5. To CKT 750 (BLK)
  6. To ground G110

RH Front Power Window Switch Circuit Description

In the UP position battery voltage applies through CKT 666 (DK BLU). Ground applies through CKT 667 (BRN). In the DN position the process reverses. Battery voltage applies directly from the WINDOWS circuit breaker to the switch. All ground paths go through the left hand front power window master switch.