GM Service Manual Online
For 1990-2009 cars only

The power mirrors contain two motors. One motor operates the mirror up and down, the other motor operates the mirror right and left. When reversing the polarity of the motors, the mirrors will move either up/down or right/left. Power is supplied to the power mirror switch via circuit 2140 (ORN) from the MIR/LOCK fuse located in the left bussed electrical center (LBEC). The ground path is supplied through the opposite contacts in the power mirror switch and circuit 1850 (BLK) from the switch to ground G203. Rotate the power mirror switch clockwise to select the right mirror and counterclockwise to select the left mirror. In order to operate the left mirror, move the selector switch to the left position. Operating the mirror in the right and left positions will power up or ground circuits 81 (WHT) and 1496 (YEL) respectfully. Operating the mirror up and down will power up or ground circuits 89 (LT GRN) and 1496 (YEL) respectfully. To operate the right mirror, move the selector switch to the right position. Operating the mirror in the right and left positions will power up or ground circuits 881 (RED/WHT) and 1496 (YEL) respectfully. Operating the mirror up or down will power up or ground circuits 1496 (YEL) and 889 (PPL/WHT) respectfully. Moving any switch in the opposite position reverses the motor polarity (utilizing the same circuits) which move the mirror accordingly.