Daytime Running Lamp: Description and Operation
Daytime Running LightsWhen you turn the ignition switch to ON (II) with the parking brake released, the DRL control unit supplies about 6 volts to the GRN/WHT wire (cavity 10), about 12 volts to the RED/WHT wire (cavity 1), and ground to the RED/GRN wire (cavity 11). This provides about 6 volts to both high beam headlights, causing them to come on at reduced brightness. If you apply the parking brake, ground is applied to the DRL control unit at the GRN/WHT wire. If the parking brake is applied before you turn the ignition switch to ON (II), the daytime mode will remain off until you release the parking brake. Once the high beams are in the daytime mode, applying the parking brake will not turn them off. When you switch to low beams, high beams, or flash-to-pass operation, ground is applied to the DRL control unit through the BLU/GRN wire, and the control unit then turns off the daytime running lights mode.