RAM 2500 Truck 2WD L6-5.9L DSL Turbo VIN 7 (2001)
Headlamp Switch: Testing and Inspection
WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, REFER TO ELECTRICAL, RESTRAINTS BEFORE ATTEMPTING ANY
STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. FAILURE TO TAKE
THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
1. Disconnect and isolate the battery negative cable. Remove the headlamp switch from the instrument panel. (Refer to LAMPS/ LIGHTING -
EXTERIOR/HEADLAMP SWITCH - REMOVAL) for the procedures. Unplug the headlamp switch wire harness connectors. Check for
continuity between the left door jamb switch sense circuit cavity of the headlamp switch wire harness connector and a good ground. There should
be continuity with the driver door open, and no continuity with the driver door closed. If OK, go to Step 2. If not OK, repair the circuit to the
driver door jamb switch as required.
2. Remove the Central Timer Module (CTM) from its mounting bracket to access the CTM wire harness connectors. (Refer to ELECTRONIC
CONTROL MODULES/BODY CONTROL CENTRAL TIMER MODULE - REMOVAL) for the procedures. Unplug the 14-way CTM wire
harness connector. Remove the key from the ignition lock cylinder. Check for continuity between the key-in ignition switch sense circuit cavity of
the 14-way CTM wire harness connector and a good ground. There should be no continuity. If OK, go to Step 3. If not OK, repair the short circuit
as required.
3. Check for continuity between the key-in ignition switch sense circuit cavities of the 14-way CTM wire harness connector and the headlamp switch
wire harness connector. There should be continuity. If OK, go to Step 4. If not OK, repair the open circuit as required.
4. Check for continuity between the left front door jamb switch sense circuit terminal and the key-in ignition switch sense circuit 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,(Refer to ELECTRONIC CONTROL MODULES/BODY CONTROL/CENTRAL TIMER MODULE - DIAGNOSIS AND
TESTING) If not OK, replace the faulty headlamp switch.
For addtional testing please refer to Powertrain Management/Computers and Controls/Body Control Module/Testing and Inspection/ See: Body and
Frame/Body Control Systems/Central Timer Module/Testing and Inspection
