Cargo Lamps
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The inadvertent power supply voltage circuit of the body control module (BCM) provides positive voltage to the cargo lamps. When the cargo lamp switch is pressed, the switch closes, ground is supplied to the cargo lamps, and the lamps illuminate. In the event that the cargo lamps were to remain on for a period of more than 10 minutes after the ignition switch is changed to the OFF position, the BCM will deactivate the inadvertent power supply voltage circuit to prevent a total battery discharge condition. Ground for the cargo lamps is supplied through the cargo lamp switch, from G203.