Ambient Light Sensor: Description and Operation

PURPOSE
The ambient light sensor is used in automatic headlamp systems to sense light levels outside the vehicle and turn on the headlamps at night and dim them for oncoming traffic.

OPERATION
The ambient light sensor monitors ambient light to control autolamp dual coil relay. As light level decreases, sensor resistance increases to preset amount energizing relays, turning on headlamps, exterior lamps and instrument illumination lamps. Sensor can be adjusted by rotating screw toward EARLIER or LATER on sensor, noting manufacturer's directions printed on unit.