GM Service Manual Online
For 1990-2009 cars only

Voltage is supplied to the outside rear view mirror switch at all times through the fuse 7 and CKT 840 (ORN) wire. Ground is provided through CKT 1850 (BLK) wire and ground G202.

In order to move the mirror to the left, set the outside rear view mirror switch to the left position. This will connect CKT 81 (WHT) to CKT 1850 (BLK) and CKT 1496 (YEL) to CKT 840 (ORN) allowing the mirror to move to the left.

Pressing the switch to the right reverses the polarity to the mirror motor in order to allow the mirror to move to the right.

In order to move the mirror upward, set the outside rear view mirror switch to the up position. This will connect CKT 1496 (YEL) to CKT 840 (ORN) and the CKT 89 (LT GRN) to CKT 1850 (BLK) allowing the mirror to move upward.

Pressing the switch down reverses polarity to the mirror motor in order to allow the mirror to move downward.

If the motor is overloaded or voltage is applied for an excessive amount of time, the ECB internal resistance increases, essentially creating an open circuit. The resistance returns to normal only after voltage is removed from the circuit, thereby restoring circuit continuity.

Power Folding Mirrors

Voltage is supplied to the outside rear view folding mirror switch through the RDO IGN Fuse 24 and CKT 1301 (DK GRN). Ground is provided through CKT 1850 (BLK) and G202.

When the EXTEND button is pressed, the extend switch is closed and CKT 190 (YEL) is energized. This action allows the mirror to extend.

When the RETRACT button is pressed, the retract switch is closed and CKT 191 (LT BLU) is energized. The action allows the mirror to retract.