Daytime Running Lamp: Description and Operation

The headlight system with daytime running lights is controlled by the Instrument Cluster. The system operates by allowing the low beam lights to operate at a reduced intensity when the vehicle is operating (the engine is running) and the normal headlights are no on. The Instrument Cluster turns the system on by grounding out the 592 CKT, thereby energizing the Daytime Running Lights Relay. This will allow a reduced voltage (6 volts) to flow across the low beam headlights. If the car has a fog lamp option, the Daytime Running Lights/Fog Light Relay will also be energized allowing normal fog lamp operation. When the normal headlights are turned on the instrument Cluster opens the 592 CKT and allows normal headlight operation.

The Instrument Cluster also has an input from the Park Brake. If the Park Brake is in the "ON" position when the ignition is cycled, the Daytime Running Lights will remain disabled until the Park Brake is put in the "OFF" position.