Low Beam System Operation

The headlamps may be turned on two different ways. First, when the ignition switch is turned to the ON position, voltage is applied to the ambient light sensor through the DEF Fuse. The ambient light sensor permanently grounds to G200. When the ambient light sensor senses a low light condition, a path to ground is provided to the coil of the headlamp relay through the ambient light sensor. This same signal is also provided to the DRL control module and disables DRL operation. Voltage is provided from the H/L Fuses, through the DRL diode to the coil of the headlamp relay. The relay contacts close providing a ground to the headlamps. The headlamps illuminate at full intensity. Second, when the end of the of the turn signal/headlamp switch lever is turned to the second detent position, the headlamps illuminate.

The Daytime Running Lamps (DRL) control module and the turn signal/headlamp switch control the headlamps. The H/L, L and H/L, R Fuses supply voltage to the headlamps, the high beam indicator and the headlamp relay through the DRL diode at all times. With the switch in the HEAD position and the dimmer switch in low, ground is provided to the low beam filaments through the dimmer switch and the closed contacts of the Headlamp Relay to G200. The low beam filaments illuminate when the ground is supplied.