Circuit Operation

The headlamp system with Daytime Running Lamps (DRL) is controlled by the Instrument Panel Cluster. The system operates by allowing the headlamps to operate at a reduced intensity when the vehicle is operating (the engine is running and transaxle is not in PARK) the the normal headlamps are not on. 'The instrument Panel Cluster turns the system on by grounding CKT' 592. thereby energizing the Daytime Running Lamps Relay (DRL). This will allow a reduced voltage (6 volts) to flow across the headlamps. If the car has fog lamps. the Day time running lamps and Fog Lamp Relay will also be energized (with the PARK lamps on) allowing normal fog lamp operation. When the Headlamp Switch is turned ON, the Instrument Panel Cluster allows normal headlamp operation.

The Instrument Panel Cluster also has an input from the Park Brake. If the Park Brake is in the ON position, the Daytime Running Lamps will remain disabled until the Park Brake is put in the OFF position. With an automatic transaxle, the Instrument Panel Cluster will also disable the DRL lamps until the transaxle has been taken out of PARK.

The Instrument Panel Cluster also Controls the Automatic Lamp Control (ALC) by grounding the ALC relay. The Instrument Panel Cluster uses a Photoresistor to determine light levels. and when to ground the ALC Relay. The Instrument Panel Cluster also grounds the Park lamp Relay to turn on the exterior lamps. Refer to Exterior Lights, for further information. When the Instrument Panel Cluster grounds the ALC Relay to turn on the headlamps, it will remove ground to the Daytime Running Lamps Relay, turning the DRL Lamps off. Lighting and Horns