Daytime Running Lamps

Daytime Running Lamp (DRL) operation is automatic provided that the Ignition Switch is in the RUN, BULB TEST or START positions, the parking brake is disengaged and the Headlamp Switch is in OFF. When DRL is operating, the High Beam Headlamps burn at a lower intensity than normal High Beam operation.

Voltage is applied through the GAUGES FUSE 4 when the Ignition Switch is in the RUN, BULB TEST or START positions to the Daytime Running Lamps (DRL) Module and to the coil (power side) of the Daytime Running Lamps (DRL) Relay. If the parking brake is disengaged and the Headlamp Switch is in the OFF position, then the DRL Module supplies ground to the coil (ground side) of the DRL Relay. With both power and ground applied to the coil of the DRL Relay, it energizes, and the contacts close. Voltage is applied through the DRL-FOG FUSE 15 and the closed contacts of the DRL Relay to the LH and RH High Beam Headlamps (now placed in a series circuit). Since the High Beam Headlamps are in series, they will burn at a lower intensity then if they were in regular High Beam operation. When DRL is operating, the DRL Module will also supply ground to the Daytime Running Lamps (DRL) indicator. Voltage is applied through the GAUGES FUSE 4 with the Ignition Switch in the RUN, BULB TEST or START positions to the DRL indicator. With both power and ground applied to the DRL indicator, it lights. If the parking brake is engaged, a ground signal is sensed at the, DRL Module. When the DRL Module receives this signal, it disables DRL operation by removing ground from the coil of the DRL Relay. The DRL Module will also disable DRL operation if the Headlamp Switch is ON or the Ignition Switch is turned to the OFF, "LOCK" or ACCY positions (also, by removing ground from the coil of the DRL Relay).