Headlights (USA)

Exterior Lights

How the Circuit Works

Low Beams
The headlight relays receive battery voltage at all times. When the headlight switch is turned 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 relays are then energized, applying battery voltage to the left and right headlights and the high beam indicator through fuses 15 and 17 (in the under-hood fuse/relay box). The low beam filaments come on because they are grounded through the dimmer switch. The high beam filaments and high beam indicator remain off because the dimmer switch interrupts their ground path.

High Beams
The headlight relays receive battery voltage at all times. When the headlight switch is turned 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. The relays are then energized, applying battery voltage to the left and right headlights and the high beam indicator through fuses 15 and 17 (in the under-hood fuse/relay box). The high beam filaments and high beam indicator come on because they are grounded through the dimmer switch. The low beam filaments remain off because the dimmer switch interrupts their ground path.

Flash-to-Pass
When the flash-to-pass switch is held in the ON position, ground is applied through the BLU/RED wire to the coils of the headlight relays. The relays are then energized, applying battery voltage to the left and right headlights and the high beam indicator through fuses 15 and 17 (in the under-hood fuse/relay box). The high beam filaments and high beam indicator come on because a path to ground is provided through the closed flash-to-pass switch.