Headlamp Switch: Testing and Inspection

WARNING: ON VEHICLES EQUIPPED WITH AIR-BAGS, REFER TO AIRBAG AND SEAT BELTS/AIR BAGS BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIR-BAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.

1. Disconnect and isolate the battery negative cable. Remove the headlamp switch from the instrument panel. Refer to Instrument Panel Systems for the procedures. Unplug the headlamp switch wire harness connectors. Check for continuity between the left front door jamb switch sense circuit cavity of the headlamp switch wire harness connector and a good ground. There should be no continuity with the driver door closed, and continuity with the driver door open. If OK, go to Step 2. If not OK, repair the circuit to the driver door jamb switch as required.
2. Check for continuity between the key-in switch sense circuit terminal and the left front door jamb switch sense terminal of the headlamp switch. There should be no continuity with the switch in the Off position, and continuity with the switch in the park or head lamps On position. If OK, see the diagnosis for the Instrument Cluster. If not OK, replace the faulty headlamp switch.