Wrangler L6-4.0L VIN S (2000)
Instrument Panel Bulb: Testing and Inspection
The diagnosis found here addresses an inoperative instrument cluster illumination lamp condition. If the problem being diagnosed includes inoperative
exterior lighting controlled by the headlamp switch, that system needs to be repaired first. If the exterior lamps controlled by the headlamp switch are
inoperative, refer to Headlamp Diagnosis. If no exterior lighting system problems are found, the following procedure will help locate a short or open in
the cluster illumination lamp circuit. If the problem being diagnosed involves a lack of dimming control for the odometer/trip odometer Vacuum
Fluorescent Display (VFD), but all of the other cluster illumination lamps can be dimmed, repair the open headlamp switch output circuit input to the
instrument cluster.
1. Check the panel lamps dimmer fuse in the fuseblock module. 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 park lamps on with the headlamp switch. Rotate the headlamp switch knob counterclockwise to just before the interior lamps detent.
Check for battery voltage at the panel lamps dimmer fuse in the fuseblock module. Rotate the headlamp switch knob clockwise while observing
the test voltmeter. The reading should go from battery voltage to zero volts. If OK, go to Step 3. If not OK, repair the open panel lamps dimmer
switch signal circuit to the headlamp switch as required. If the circuit tests OK, refer to Headlamp Diagnosis.
3. Disconnect and isolate the battery negative cable. Remove the instrument cluster. Turn the headlamp switch off. Remove the panel lamps dimmer
fuse from the fuseblock module. Probe the fused panel lamps dimmer switch signal circuit cavity of the instrument cluster wire harness connector
A. Check for continuity to a good ground. There should be no continuity. If OK, go to Step 4. If not OK, repair the shorted fused panel lamps
dimmer switch signal circuit as required.
4. Install the panel lamps dimmer fuse in the fuseblock module. Connect the battery negative cable. Turn the park lamps on with the headlamp
switch. Rotate the headlamp switch knob counterclockwise to just before the interior lamps detent. Check for battery voltage at the fused panel
lamps dimmer switch signal circuit cavity of the instrument cluster wire harness connector A. If OK, replace the faulty cluster illumination lamp
bulb(s) and bulb holder(s). If not OK, repair the open fused panel lamps dimmer switch signal circuit as required.
