Cargo Lamp and Underhood Lamp
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2002 GMC Yukon XL, 2002 GMC Yukon, 2002 Chevrolet Tahoe, 2002 Chevrolet Suburban, and 2002 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
The inadvertent power relay provides battery positive voltage to the cargo lamp and the underhood lamp. When the respective normally open switch is closed, the switch provides a ground circuit and the lamp illuminates. The cargo lamp is grounded at G203. The underhood lamp is grounded at G102.