Grand Cherokee 4WD V8-4.7L VIN N (2000)
Four-Wheel Drive (4WD) Indicator Lamp: Testing and Inspection
FOUR-WHEEL DRIVE INDICATOR LAMP - PART TIME
This lamp depends upon a hard wired circuit input to the instrument cluster for proper operation. The following procedures will help to diagnose
conditions that may cause an inoperative hard wired lamp circuit condition.
WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, REFER TO AIR BAGS 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 AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
The diagnosis found here addresses an inoperative four-wheel drive indicator lamp condition. If the problem being diagnosed is related to lamp
accuracy, be certain to confirm that the problem is with the lamp or switch and not with a damaged or inoperative transfer case or transfer case
linkage. If no transfer case problem is found, the following procedure will help locate a short or open in the indicator lamp circuit.
Procedure
1. Check the fused ignition switch output (RUN/START) fuse in the junction block, If OK, go to Step 2. If not OK, repair the shorted circuit or
component as required and replace the faulty fuse.
2. Turn the ignition switch to the ON position. Check for battery voltage at the fused ignition switch output (RUN/START) fuse in the junction
block. If OK, go to Step 3. If not OK, repair the open fused ignition switch output (RUN/START) circuit to the ignition switch as required.
3. Turn the ignition switch to the OFF position. Disconnect and isolate the battery negative cable. Disconnect the transfer case switch wire
harness connector. Check for continuity between the ground circuit cavity of the transfer case switch wire harness connector and a good
ground. There should be continuity. If OK, go to Step 4. If not OK, repair the open ground circuit to ground as required.
4. Connect the battery negative cable. Turn the ignition switch to the ON position. Install a jumper wire between the part time four wheel drive
indicator lamp driver circuit cavity of the transfer case switch wire harness connector and a good ground. The part time four-wheel drive
indicator lamp should light. If OK, replace the faulty transfer case switch. If not OK, go to Step 5.
5. Turn the ignition switch to the OFF position. Disconnect and isolate the battery negative cable. Remove the instrument cluster. With the
transfer case switch wire harness connector still disconnected, check for continuity between the part time four wheel drive indicator lamp
driver circuit cavity of the instrument panel wire harness connector for the instrument cluster and a good ground. There should be no
continuity. If OK, go to Step 6. If not OK, repair the shorted part time four wheel drive indicator lamp driver circuit as required.
6. Check for continuity between the part time four wheel drive indicator lamp driver circuit cavities of the instrument panel wire harness
connector for the instrument cluster and the transfer case switch wire harness connector. There should be continuity. If OK, replace the faulty
bulb. If not OK, repair the open part time four wheel drive indicator lamp driver circuit as required.
