Vanity Lamps
WARNING: This page is about a different car, the 2003 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.
Battery positive voltage is applied at all times to the MONITORED LD relay 37 coil and switch side. The BCM applies a ground to the MONITORED LD relay 37 coil side, energizes the relay, and closes the switch contacts. Then the BCM allows battery positive voltage to the MONITORED LD fuse 2 and to the vanity mirror lamps. When the vanity mirror cover on the sunshade is opened, its switch closes providing a ground circuit, and the vanity lamp illuminates.