Circuit/System Description

WARNING: This page is about a different car, the 2007 Saturn Sky. However, it is still accessible from the selected car via links, so may be relevant.

With the headlamp switch in the HEAD position, the headlamp switch headlamp ON signal circuit is grounded through the turn signal/multifunction switch at G300. In response to this input, the body control module (BCM) provides ground to either the headlamp low beam relay control circuit or the headlamp high beam relay control circuit. The position of the headlamp dimmer switch determines which relay coil has ground. The BCM supplies ground to the relay coil circuits, if the headlamps are necessary. The underhood fuse block supplies battery positive voltage to both relay switch circuits. When the low beam relay coil is energized, current flows through the LT LOW beam and the RT LOW beam fuses to the low beam headlamps. When the headlamp high beam relay coil is energized, current flows through the LT HI beam and the RT HI beam fuses to the high beam headlamps. Ground for the left headlamp assembly is provided at G101. Ground for the right headlamp assembly is provided at G102. For more detailed information concerning headlamp operation refer to Exterior Lighting Systems Description and Operation .