Headlamp Circuit

The right hand headlamp fuse supplies battery positive voltage from the IP fuse block to the right headlamp. The left hand headlamp is fed battery positive voltage from the DRL relay. The low beam and high beam circuits are joined together and provide the Body Control Module (BCM) with a low and high beam input. The low beam and high beam circuits continue to the headlamp switch. The headlamp switch includes the dimmer switch and the flash-to-pass switch. When the headlamp switch is placed in the headlight ON position a path to ground is provided. Depending on the position of the high/low beam (dimmer) switch, either the low or high beam circuit now have power and ground.

When the headlamp dimmer switch handle is pulled toward the driver, the flash-to-pass switch closes grounding the high beam circuit. Both high beams will remain on until the driver releases the switch handle.

The ambient light sensor is a light sensitive transistor that varies its voltage signal to the Body Control Module (BCM) in response to changes to the outside (ambient) light level.