Lighting and Horns: Description and Operation

GENERAL INFORMATION
LH vehicles use lighting on the interior and exterior of the vehicle for illuminating and indicating purposes. Lighting circuits are protected by fuses or circuit breakers. Lighting circuits require an overload protected power source, on/off device, lamps and body ground to operate properly. Plastic lamp sockets require a wire in the harness to supply body ground to the lamp socket. Lamp sockets that are exposed to moisture should be coated with Mopar� Multi-purpose Grease or equivalent to avoid corrosion. If a socket has become corroded, clean socket and bulb base with abrasive fiber sanding pad or metallic bristle brush. Replace sockets and bulbs that are deformed from corrosion that could prevent a continuous body ground.

Wire connectors can make intermittent contact or become corroded. Before coupling wire connectors, inspect the terminals inside the connector. Male terminals should not be bent or disengaged from the insulator. Female terminals should not be sprung open or disengaged from the insulator. Bent and sprung terminals can be repaired using needle nose pliers and pick tool. Corroded terminals appear chalky or green. Corroded terminals should be replaced to avoid recurrence of the problem symptoms. Wire connector terminals should be coated with Mopar� Multi-purpose Grease or equivalent to avoid corrosion.

Begin electrical system failure diagnosis by testing related fuses and circuit breakers in the fuse block and engine compartment. Verify that bulbs are in good condition and test continuity of the circuit ground.

INTRODUCTION
Interior Lighting
The interior lamps system is powered at all times by the 10 amp fuse located in cavity 13 of the junction block. This is the Ignition-Off Draw (IOD) fuse. Circuit M1 is connected from the junction block to the trunk lamp, vanity lamps, door courtesy lamps, overhead lamps, and various other components.

Power for the M1 fuse is supplied by circuit A7 from the Power Distribution Center (PDC), and is protected by a 20 amp fuse located in cavity G.

Front Lighting
This information of the wiring diagrams covers the front lighting systems for all the LH vehicles. If there is a difference in operation of the systems it will by identified in the circuit descriptions and the diagrams.

The headlamp switch has three positions, OFF, PARK (parking lamps), and ON. Power for the headlamp portion of the headlamp switch is provided on circuit A3. This circuit originates in the Power Distribution Center (PDC) and is protected by a 30 amp fuse located in cavity H.

Power for the parking lamp portion of the head-lamp switch is provided on circuit F33. Circuit A13 in the Power Distribution Center (PDC) powers a 15 amp fuse located in cavity 9 of the junction block. The A13 circuit is protected by a 20 amp fuse located in cavity F of the PDC. Circuit F33, which connects to the other side of the fuse in the junction block, connects to the headlamp switch and is spliced to provide power for the instrument cluster.

Rear Lighting
This information of the wiring diagrams covers the rear lighting systems for all the LH vehicles. If there is a difference in operation of the systems it will by identified in the circuit descriptions and the diagrams.


CIRCUIT OPERATION
Illumination Lamps
The Body Control Module (BCM) controls the intensity of the following lamps based on a input received from the dimmer switch on circuit E19:
- Radio illumination lamps
- A/C-Heater control lamps
- ATC control lamps
- Ash receiver lamp
- Instrument cluster lamps
- Traction control switch lamp
- Headlamp switch illumination lamp