Voltage to the coil of the courtesy lamp relay, dome, reading lamp, courtesy lamps, cargo Lamp, instrument panel (IP) compartment lamp and the underhood lamp is supplied from the Inadvertent power relay on CKT 1732. The inadvertent power relay receives voltage from the CTSY LP fuse which is hot at all times. Ground for the courtesy lamps goes through the courtesy lamp relay. Both relays are controlled by the body control module (BCM) base on inputs from door jamb switch, dome lamp switch or door handle switch. The BCM will supply a ground to the courtesy lamp relay when closing any one of the above switches to ground. Ground for the reading lamp, cargo lamp, IP compartment lamp and the underhood lamp is supplied by its own ground.

Voltage to the ash tray lamp and power window/door lock switches is supplied from the INT PRK fuse. Voltage to the INT PRK fuse is supplied from the park lamp relay, and is hot when park lamps or headlamps are on.

With the headlamp and panel dimmer switch in the park or head position, voltage is supplied to the instrument panel (IP) dimmer switch via CKT 44. The voltage output of the IP dimmer is veritable and goes through the ILLUM fuse via CKT 8 to the cluster, radio and various IP switches. For the radio and cluster displays and some switches, an additional circuit is required, CKT 1382, for the these components to dim. CKT 1382 is a 12 volt output of the BCM, and is hot when park or headlamps are on.

Some circuits are monitored by the BCM, and upon failure may set a DTC.