The exterior lighting system consist of the following lamps:

The HDLP SW fuse in fuse block 1 supplies battery positive voltage to the headlamp switch. With the headlamp switch in the HEADLAMP position, battery positive voltage is supplied to the headlamp dimmer switch. With the headlamp dimmer switch in the HIGH BEAM position, battery positive voltage is supplied directly to the high beam headlamps. With the headlamp dimmer switch in the LOW BEAM position, the headlamps dimmer switch supplies battery positive voltage to the switch side of the daytime running lamps (DRL) relay, and to the low beam headlamps. Both headlamps are grounded at G101 or G102.

The daytime running lamps will illuminate the low beam headlamps at a reduced intensity. The daytime running lamps (DRL) will operate when the ignition is ON, the headlamp switch is OFF, and the park brake is disengaged. The HDLP SW fuse in fuse block 1 supplies battery positive voltage to the headlamp switch. The headlamp switch then supplies battery positive voltage to the DRL relay, through the DRL diode. The DRL diode drops the amount of voltage going to the DRL relay. Ignition voltage is supplied to the coil side of the DRL relay by the IGN 1 circuit breaker in the instrument panel (IP) fuse block. The DRL control module supplies ground to the switch side of the DRL relay. This activates the DRL relay and supplies voltage to the low beam headlamps. Both headlamps are grounded at G101 or G102.

The park lamps are illuminated when the headlamp switch is placed in either the PARK or HEADLAMP position. The TLMKR circuit breaker in the instrument panel (IP) fuse block supplies battery positive voltage to the switch side of the lighting relay. The coil side of the lighting relay is grounded at G101 or G102. When the headlamp switch is placed in the PARK or HEADLAMP position, battery positive voltage is supplied to the coil side of the lighting relay. This activates the lighting relay. The lighting relay then supplies battery positive voltage to splice 212. Splice 212 distributes the battery positive voltage to the park lamps and to the upfitter connector. The park lamps are grounded at G101 or G102.

The HAZ circuit breaker in the instrument panel (IP) fuse block supplies battery positive voltage to the hazard lamps flasher. The hazard lamps flasher is grounded at G101 or G102. The hazard lamps flasher supplies battery positive voltage to the turn signal switch and the hazard warning switch. When the turn signal switch is placed in either the left or right turn position, the circuit is complete from the hazard lamps flasher to the turn signal lamps and to ground. The hazard lamps flasher then sends an on-off voltage signal to either the left or right turn signals and their instrument panel cluster (IPC) indicator. When the hazard warning switch is placed in the ON position, the circuit is complete from the hazard lamps flasher to all turn signal lamps and to ground. The hazard lamps flasher sends an on-off voltage signal to all the turn signals and their IPC indicators. During turn signal and hazard lamps operation, on-off voltage is also supplied to the upfitter connector. The front turn signal lamps are grounded at G101 or G102.

The STOP LP circuit breaker in the instrument panel (IP) fuse block supplies battery positive voltage to the stop lamp switch. When the brake pedal is pressed, the stop lamp switch provides battery positive voltage to the upfitter connector.

The B/U circuit breaker in the instrument panel (IP) fuse block provides ignition positive voltage to the backup lamp switch or the park/neutral position and backup lamp switch. When the transmission is placed in reverse, the backup lamp switch or the park/neutral position and backup lamp switch provides voltage to the upfitter connector.