GM Service Manual Online
For 1990-2009 cars only

Each outside rearview mirror has two reversible motors. One motor adjusts the mirror up and down. The other motor adjusts the mirror left and right. The motors are controlled by the outside rearview mirror remote control switch. The outside rearview mirror remote control switch consists of two different switches. The mirror select switch is used to select the mirror to be adjusted. The mirror position switch controls the movement of the selected mirror.

The power mirror system has voltage applied by the PWR MIRROR fuse through circuit 1140 to the outside rearview mirror remote control switch. When the left mirror is selected with the select switch, the mirror position switch controls the left mirror. When the position switch is pressed to the up position, voltage is applied through circuit 1499 to the up/down motor of the left mirror. Ground is applied from G302 through circuit 750, the outside rearview mirror remote control switch and circuit 88 to the up/down motor. The left mirror moves up. When the position switch is pressed to the down position, voltage is applied through circuit 88 to the up/down motor of the left mirror. Ground is applied through circuit 1499 to the up/down motor. The voltage polarity to the left mirror is reversed and the mirror moves down. The left/right motor of the left mirror operates similar to the up/down motor. When the position switch is pressed to the left position, voltage is applied through circuit 1499 to the left/right motor of the left mirror. Ground is applied through circuit 81 to the left/right motor. The left mirror moves to the left. When the position switch is pressed to the right position, voltage is applied through circuit 81 to the right/left motor of the left mirror. Ground is applied through circuit 1499 to the right/left motor. The voltage polarity to the left mirror is reversed and the mirror moves to the right.

The right mirror operates the same way when the mirror select switch is moved to the right position.

Each mirror motor contains an internal electronic circuit breaker. If a mirror position switch is held in the up/down position or the left/right position after the mirror movement stops, the circuit breaker opens to protect the motor. The circuit breaker also opens to stop the motor if the mirror becomes obstructed during operation. The circuit breaker resets when the voltage to the motor is interrupted.