Daytime Running Lamps (DRL)

The Daytime Running Lamps (DRL) control module is designed to automatically operate exterior lights depending on outside light conditions. The DRL control module operates in two modes: the day mode and the low light mode. In the day mode the DRL ambient light sensor senses daylight. Then, the DRL control module turns on the high beam headlamps at reduced intensity under the following conditions:
^ The ignition switch is in the RUN position.
^ The headlamps are off.
^ The park brake is OFF (released).

In the low light mode, the DRL ambient light sensor senses darkness. Then turns off the high beam headlamps and turns on the low beam headlamps through circuit 10 and turns on the park, side marker, license, and tail lamps through circuit 9. If the engine should stall with the DRL control module in the low light mode, the DRL control module turns off the headlamps and leave the side marker, park, license and tail lamps on while the engine is being cranked. The headlamp and instrument panel lamp dimmer switch operates as usual. The DRL control module receives voltage from Fuse 33 through circuit 1439 and Fuse 4 through circuit 41. The park lamps and/or the headlamps may be operated manually at any time by using the headlamp and instrument panel lamp dimmer switch. The DRL module does not operate if the system voltage is less then 9 volts or greater than 18 volts.