I/P Compartment Lamp
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2003 GMC Yukon XL, 2003 GMC Yukon, 2003 Chevrolet Tahoe, 2003 Chevrolet Suburban, and 2003 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
The inadvertent power courtesy lamps supply voltage circuit of the BCM provides battery positive voltage to the instrument panel compartment lamp. When the I/P compartment is opened, a switch closes to provide a ground circuit and the I/P compartment lamp illuminates. Ground is provided to the I/P compartment lamp at G203.