Daytime Running Lamp: Description and Operation

HEADLAMPS
Voltage is supplied to the Daytime Running Lamps Relay at all times through the ORN (340) wire from the DRL Fuse and when the Ignition Switch is in RUN through the PNK/BLK (39) wire from the GAGES Fuse. The relay provides voltage to the LH High Beam through the DK BLU/ORN (593) wire. This wire also becomes the ground wire when the Headlamps are operating normally.

Voltage is supplied to the Daytime Running Lamps Module when the Ignition Switch is placed in RUN through the PNK/BLK (39) wire and the GAGES Fuse. When the Ignition Switch is placed in RUN, the voltage from the relay is provided a ground path through the LT GRN (11) wire through the module. This enables the relay to provide voltage to the High Beam Lamps in series causing the lamps to share the voltage resulting in the lamps operating at half intensity.

The module will not enable the relay if the Light Switch is placed in the ON position or the Park Brake Switch is ON.

The HI Beam Indicator also receives voltage from the module when the Headlamp Dimmer Switch is in the High position.

FOG LAMPS
Voltage is supplied to the Fog Lamp Relay at all times through the LT BLU (316) wire and the Fog Lamps Fuse. When the Fog Lamp Switch is ON. voltage is supplied to the coil of the Fog Lamp Relay through the YEL (317) wire. Ground for the relay is provided through the Daytime Running Lamps Module and the DK GRN (1317) wire. With the relay energized, voltage is provided to the indicator lamp through the PPL (34) wire and the Fog Lamps through the PPL (34) wire and the PPL/WHT (134) wires. Ground for the Fog Lamps are provided through the BLK (154) wires and ground G154.

If the headlamps are on high beam, voltage is supplied to LT GRN (11) wire and the high beam elements of the headlamps. This removes the ground for the Fog Lamp Relay and de-ergizes the circuit.