Grand Cherokee 4WD V8-4.7L VIN N (2000)
Cigarette Lighter Relay: Testing and Inspection
Cigar Lighter Relay
The cigar lighter relay is located in the junction block, below the driver side end of the instrument panel in the passenger compartment.
WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, REFER 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.
1. Remove the cigar lighter relay from the junction block.
2. A relay in the de-energized position should have continuity between terminals 87A and 30, and no continuity between terminals 87 and 30. If OK,
go to Step 3. If not OK, replace the faulty relay.
3. Resistance between terminals 85 and 86 (electromagnet) should be 75 ± 5 ohms. If OK, go to Step 4. If not OK, replace the faulty relay.
4. Connect a battery to terminals 85 and 86. There should now be continuity between terminals 30 and 87, and no continuity between terminals 87A
and 30. If OK, perform the Relay Circuit Test that follows. If not OK, replace the faulty relay
Relay Circuit Test
1. The relay common feed terminal cavity (30) of the junction block is connected to battery voltage and should be hot at all times. Check for battery
voltage at the fused B(+) circuit cavity in the junction block receptacle for the cigar lighter relay. If OK, go to Step 2. If not OK, repair the fused
B(+) circuit to the Power Distribution Center (PDC) fuse as required.
2. The relay normally closed terminal (87A) is connected to terminal 30 in the de-energized position, but is not used for this application. Go to Step
3.
3. The relay normally open terminal (87) is connected to the common feed terminal 30. in the energized position. This terminal supplies battery
voltage to the fused B(+) fuse in the junction block that feeds the cigar lighter when the relay is energized by the ignition switch. There should be
continuity between the junction block cavity for relay terminal 87 and the fused B(+) fuse in the junction block at all times. If OK, go to Step 4. If
not OK, repair the open fused B(+) circuit to the junction block fuse as required.
4. The coil ground terminal (85) is connected to the electromagnet in the relay. It receives battery feed to energize the cigar lighter relay when the
ignition switch is in the Accessory or On positions. Turn the ignition switch to the On position. Check for battery voltage at the fused ignition
switch output (ACC/ run) circuit cavity for relay terminal 85 in the junction block receptacle for the cigar lighter relay If OK, go to Step 5. If not
OK, repair the open fused ignition switch output (ACC/run) circuit to the ignition switch as required.
5. The coil battery terminal (86) is connected to the electromagnet in the relay. The junction block cavity for this terminal should have continuity to
ground at all times. If not OK, repair the open ground circuit to ground as required.