Daytime Running Lamp: Description and Operation

CIRCUIT OPERATION
The head lamps receive battery voltage through the HEAD L and HEAD R Fuses at all times. When the Headlight Switch is in the head position, a ground is provided through the Daytime Running Lights (DRL) controller and the Headlight/Dimmer Switch at G200. When the Headlight Switch is in the OFF or PARK position, a ground is provided through the DRL controller and the DRL resistor at G101 provided that all conditions for Daytime Running Lights operation are met. High and low-beam selection is provided by grounding the high and low-beam filaments separately. The high-beam filaments are grounded through the Headlight/Dimmer Switch at G200. The low-beam filaments are grounded through the DRL controller and the Headlight/Dimmer Switch at G200.

The Daytime Running Lights system operates the low-beam head lamps at a lower intensity than the vehicle's regular low-beams. Daytime Running Light system operation is initiated when the DRL controller senses all of the following:
^ A charge input signal from the generator at terminal 5, indicating an "engine running" condition.
^ No ground signal from the parking brake switch at terminal 4, indicating that the parking brake is not engaged.
^ A "lights OFF" signal at terminal 11, indicating the Headlight/Dimmer Switch is in either the "OFF" or PARK position.

The DRL controller receives battery voltage for system operation at terminal 7 from the IG-COIL METER Fuse whenever the ignition switch is in the "ON" or "START" position. The DRL controller is permanently grounded at G201 through terminal 8.