Headlights (Canada: SC)

How the Headlights Circuit Works (Canada: SC)

Low Beams

The headlight relays receive battery voltage at all times. When the headlight switch is moved to the HEAD position with the dimmer switch in LOW, ground is applied through the BLU/RED wire to the coils of the headlight relays. The headlight relays are then energized, applying battery voltage to the left and right low and high beam headlights through fuses 15 and 17 (in the under-hood fuse/relay box).The low beam headlights illuminate because they are grounded directly to the body of the vehicle.

High Beams
The headlight relays and the coil of the DRL relay receive battery voltage at all times. When the headlight switch is moved to the HEAD position with the dimmer switch in HIGH, ground is applied through the BLU/RED wire to the coils of the headlight relays and DRL relay. The headlight relays are then energized, applying battery voltage to the left and right low and high beam headlights through fuses 15 and 17 (in the under-hood fuse/relay box). The high beam headlights and high beam indicator illuminate because a path to ground is provided through the energized DRL relay to the dimmer switch. The low beam headlights will illuminate because they are grounded directly to the body of the vehicle.

Flash-to-Pass
When the flash-to-pass switch is moved to the ON position, ground is applied through the BLU/RED wire to the coils of the headlight relays and the DRL relay. The the headlight relays are then energized, applying battery voltage to the left and right low and high beam headlights through fuses 15 and 17 (in the under-hood fuse/relay box). The high beam headlights and and high beam indicator illuminate because a path to ground is provided through the energized DRL relay to the flash-to-pass switch. The low beam headlights illuminate because they are grounded directly to the body of the vehicle.

Daytime Running Lights
Battery voltage is supplied to the DRL control unit through fuse 3 (in the under-dash fuse relay box). With the ignition switch in ON (II) and the parking brake released, the DRL control unit provides battery voltage to the left high beam headlight. Because the DRL relay is not energized, the ground path is interrupted, and battery voltage flows through the left high beam headlight to the right high beam headlight. The DRL control unit provides a ground for the right high beam headlight, which allows the high beam headlights to operate in series.

When the parking brake is engaged, the DRL control unit will discontinue daytime running light operation.