Canada

How the Circuit Works

Daytime Running Lights

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. It 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.

Low Beams

The headlight relay receives battery voltage at all times. When you turn the headlight switch to the HEAD position with the dimmer switch in LOW, ground is applied through the BLU/RED wire to the coil of the headlight relay. This energizes the relay, applying battery voltage to the left and right low beam headlights through fuses 45 and 46. The low beam bulbs come on because the opposite terminal is tied to ground through the low beam cut relay and dimmer relay.

High Beams

When you pull the dimmer switch to HIGH with the low beams already on, ground is applied to the dimmer relay from the dimmer switch. This energizes the dimmer relay, applying ground through the WHT/BLU wires to the daytime running lights control unit. The control unit applies ground through the RED/BLU (cavity 11) and YEL/BLU (cavity 1) wires to the high beam bulbs and high beam indicator, which turns on the high beams and indicator light. The low beam headlights go off because their ground path is interrupted by the activated dimmer relay.

Flash-to-Pass

When you hold the flash-to-pass switch in the ON position, ground is applied through the BLU/RED wire to the coil of the headlight relay and through the RED/BLU wire to the coil of the dimmer relay. This energizes the headlight relay, applying battery voltage to the low and high beam bulbs and to the dimmer relay. As the high beam bulbs receive battery voltage, the dimmer relay is energized, applying ground through the WHT/BLU wires to the daytime running lights control unit. The control unit applies ground through the RED/BLU (cavity 11) and YEL/BLU (cavity 1) wires to the high beam bulbs and high beam indicator, which turns on the high beams and indicator light. The low beams go off because their ground path is interrupted by the activated dimmer relay.