Daytime Running Lamp: Description and Operation

DAYTIME RUNNING LAMPS (DRL)
Daytime running lamps (DRL) are standard equipment on all models. Operating through the low beams at 80 percent intensity of the normal output, the DRL system operates under the following conditions:
- When the engine is running.
- When the parking brake is not applied.
- When the turn signal/headlamp switch lever is in either the OFF or the park lamp position.
- When the ambient light sensor senses a bright light condition.

The DRL control module receives voltage through the IG fuse when the ignition switch is in the ON or START position and is permanently grounded at G200.

The following will prevent DRL operation:
- When the parking brake is engaged, the parking brake switch closes, providing a ground to the DRL control module, disabling the DRL operation.
- When the generator is not running, a switch in the generator closes, providing a ground to the DRL control module, disabling the DRL operation.
- When the turn signal/headlamp switch is in the headlamp position, providing a ground to the DRL control module, disabling the DRL operation. When all of the conditions for DRL operation are met, the DRL control module provides a ground for the low beam filaments in the headlamps through the DRL control module to G200. The H/L, L and H/L, R Fuses supply the voltage to the headlamps at all times. The low beam filaments will light at 80 percent intensity.