IP Compartment Lamp
WARNING: This page is about a different car, the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, and 2003 Chevrolet Cab & Chassis Silverado. 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 IP compartment is opened, a switch closes to provide a ground circuit and the IP compartment lamp illuminates. Ground is provided to the IP compartment lamp at G203.