Circuit Description
WARNING: This page is about a different car, the 2003 Oldsmobile Bravada, 2003 GMC Envoy XL, 2003 GMC Envoy, and 2003 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
The driver door module supplies battery positive voltage to the power mirror switch. When the mirror direction switch is placed in the up or down position, the appropriate signal circuit is switched to battery voltage. The driver door module senses the voltage change and activates the selected outside rearview mirror in the appropriate direction.