Daytime Running Lamp: Description and Operation

When you turn the ignition switch to ON (II) with the parking brake released, the daytime running lights control unit supplies about 6 volts to the RED/GRN wire (cavity 10), about 12 volts to the YEL/BLU wire (cavity 1), and ground to the RED/BLU wire (cavity 11) This provides about 6 volts to both high beam headlights, causing them to come on at reduced brightness. At the same time, about 12 volts energizes the coil of the low beam cut relay, removing the ground path to the low beams. If you apply the parking brake, ground is applied to the daytime running lights 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 beam, high beam, or flash-to-pass operation, ground is applied to the daytime running lights control unit through the BLU/RED wire, and the control unit then turns OFF the daytime running lights mode.