Circuit/System Description

When the BCM receives a signal to command the courtesy lamps ON, it applies battery voltage through the dome/courtesy lamps control circuit to the courtesy lamps. The door sill illumination receives voltage through the courtesy lamps circuit. The door sill illumination harness connector includes a power inverter which converts the battery voltage to 150 V AC (550 Hz). This AC voltage is supplied to the door sill lamps and causes them to illuminate.