Circuit Description
WARNING: This page is about a different car, the 2004 Pontiac Aztek and 2004 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.
The headlamp switch provides a direct ground input into the body control module (BCM) for the headlamp switch input when the switch is activated. This input is used by the BCM in order to control the headlamps when the headlamp switch is in the HEAD position.