IP Compartment Lamp
WARNING: This page is about a different car, the 2003 Pontiac Aztek and 2003 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.
The courtesy lamps supply voltage circuit also provides battery positive voltage to the instrument panel compartment lamp. When the IP compartment is opened, its switch closes to provide a ground circuit and the IP compartment lamp illuminates.