Tail lights do not work, but front parking lights do. All exterior lights work except rear tail/park lights. Lamps are good.

IN THE FUSE BOX. (CAB OR BAY_)
THE OLD USERS GUIDE AND THE SERVICE MANUAL COVERS FUSES.
PARKS = TAILS
PARKS ARE FRONT REAR. BOTH
SO ARE BOTH ENDS OF CAR DEAD FOR PARKS?
THE FUSE IS MARKED "TAIL"
AND RUNS ALL 10 PARK LAMPS ON THE CAR.
THE PARK FEED TO TAIL OF CAR PASSES TROUGH A LIGHT FAILURE SENSOR ON 4 REAR TAIL LAMPS ONLY
THE SENSORS IS OPTIONAL AND NEEDS FUSE "GAUGE" NOT BLOW TOO., THIS OPTION SO FITTED, HAS CLUSTER LAMP CALLED
"REAR LIGHT " WARNING

REPOST AND TELL WHAT ALL 10 PARKS DO.
OTHER WISE HUGE WORK DOING THE HARDWAY

FRONT, REAR AND SIDE MARKER ARE ALL PARK LAMPS
THE LEGACY NAME TAIL IS STILL USED BACK TO 1920.
SO IS A TRADITION BUT BIG TIME CONFUSING WITH 10 LAMPS.
LIKE SAYING MY FRONT TAIL LAMPS ARE DEAD., SILLY.

no car told
not one clue, year,maker or model
Tail spark, parks go to 4sides 4 corners and lic, lamps. 10 lamps.
even more with parks on mirror L/R

on newer cars there is no fuse,
they use BCM, the body brain.
and it uses smart electronic regulators for lamps
that self correct if the short is cured.
common shorts are, trailer hitch hack jobs.
or collision damage never fully corrected.
MOST BCM slip the park feeds 4 waYS, F/R AND L/R
SO TELL IF ALL 10 LAMPS PARK ARE BAD

THE WORD TAIL WAS FOR TIN LIZZY DAYS, 1 REAR TAIL
AND NOW IS 10 PARKS. OR MORE.
NO CAR TOLD OR I'D OF POSTED THE SCHEMATIC TO IT.

USA car, must we guess, #1 fact to know?
so front parks work and rear parks(called tails wrong) only rear bad and side parks good? cars can have 10 parking lamps. do they all fail., a key fact to know for what's wrong.
is real license lamp dead too (3 park rear)
I have KJ jeep service manual open now, (PDF) owned .
Daytime Running Lights - If Equipped<<< got this????? DRL
the uses guide is free from jeep 24/7, no need to work blind. ever.
causes for rear dead

• BCM failing
• fuse 9 and 7 blown ,7 is left, so both are not blown.
• park relay bad.
• g304 ground bad,

say no to all 4
#5 is 2 bad lamps, buy them put them in.
g304 bad kills lots of lamps rear os is not that.

not told at all
engine OK and drives perfect and head lamps work ,high and low beams.
nor if front parks works
no if DRL is on the car (an options)
does heater blower work//
does radio work,
do dome lamps work doors open.
does the IP cluster work right.?
4 turn sigals all work and hazards.
stop lamps work
reverse lamps work.

if all works , but rears
then fuses are not blown
BCM must be good, or the park relay dies and all parks fail not just rear.
there rear lamps are both burned out or the REAR G304 ground is bad.
but g304 runs most things on rear,so it can not be bad.
so 2 lamps burned out, we test the lamps now.
not telling all good and bad, the answer is way too long
electrics are a complex tree structure.

What about them ? What front lights ? Headlamps , park lamps, marker lamps ? They don't work ?

Exterior Lamps
The exterior lighting system consist of the following lamps:
• The Headlamps
• The Daytime Running Lamps (DRL)
• The Clearance Lamps (Y92 roof rack only)
• The Cornering Lamps
• The Front Fog Lamps
• The Rear Fog Lamps (Export)
• The Park, Tail and Marker Lamps
• The Turn Signal Lamps
• The Stop Lamps
• The Backup Lamps

Park, Tail, Marker, License, and Clearance Lamps
The park, tail, marker, license, and clearance (Y92 only) lamps are turned on when the headlamp switch is placed in the PARK or ON position or anytime the headlights are requested. The I/P BATT fuse in the engine wiring harness junction block supplies battery positive voltage to both the park lamp relay switch contacts and the park lamp coil circuit. The body control module (BCM) provides a ground or control circuit to the park lamp relay coil circuit. When the park lamps are turned on, the BCM energizes the park lamp relay. Current flow is from the park lamp relay to the individual park lamp circuit fuses and to their respective park, tail, marker, and license lamps. The front park and marker lamps are grounded at G107 and G103. The tail lamps are grounded at G401 and G402. The license lamps are grounded at G401. When equipped with the Y92 roof rack option, the clearance lamps are grounded at G302. If the driver places the headlight switch in the ON position after the ignition switch has been turned OFF, the park, tail, marker, license, and clearance lamps will remain on until turned off or the battery runs dead.
The T PARK fuse in the rear fuse-relay block supplies battery positive voltage to a separate park lamp circuit connected to the trailer wiring harness.

Your front park lamps and rear tail lamps, use the same fuse and park lamp relay. So if the front park lamps work it's not the fuse or relay. The problem should be the wire circuit. The wire color for voltage at rear tail lamps is violet with white tracer. Use a test light and check for voltage, lamps turned on.
Your stop and turn work ok, correct?

Do your headlamps work ?
Park/Marker/License/Tail Lamps
Voltage is applied to the turn/headlamp switch at all times. When the turn/headlamp switch is in the PARK or the HEAD position, voltage is applied to the following components:
?€¢
The park lamps

?€¢
The marker lamps

?€¢
The tail lamps

?€¢
The license lamp

The front marker lamps are grounded through the turn filament of the respective front park/turn lamp. The front marker lamps light as a result.
The automatic lamp control function turns on the park lamps and the headlamps. This action occurs when the ambient light sensor determines that the exterior lamps should be turned ON based on the amount of available light. When the BCM grounds the park lamp relay, voltage is supplied directly to the park lamps, bypassing the turn/headlamp switch assembly. When this action occurs, the following conditions exist:
?€¢
The automatic lamp control relay is grounded.

?€¢
The headlamps turn ON. Refer to Headlights/Daytime Running Lights (DRL) Circuit Description .

The lamps turn OFF when the BCM does not ground the park lamp relay or the automatic lamp control relay. This action is caused by the following conditions:
?€¢
The available light reaches a predetermined level.

?€¢
The ignition switch is turned to the OFF position

Park lamp fuse 20amp located in the under hood fuse box .DRL control module
Daytime Running Lamps (DRL) Control Module
Right of the steering column, behind the IP
Park, Sidemarker, Tail and License Lamps
Voltage is applied continuously to the PARK fuse to the headlamp and the instrument panel (IP) lamp dimmer switch through CKT 1340.
When the headlamp and the (IP) lamp dimmer switch is in the PARK or HEAD position, voltage is applied to CKT 9 thus activating the following lamps:
• The park lamps
• The side marker lamps
• The tail lamps
• The license lamps
The park/turn lamps are the only lamps that do not activate yet receive a current from CKT 9. The park/turn lamps do not activate because the voltage drop across the front side marker lamps is much higher than that across the turn lamp filaments Step
Action
Normal Result(s)
Abnormal Result(s)*

1
Turn the headlamp/instrument panel (IP) lamp dimmer switch to the PARK position.
The following lamps light:
• The license plate lamps
• The taillight lamps
• The front side marker lamps (Domestic)
• The front parking lamps (Domestic)
The headlamp position lamps (Export)
Refer to Park Lamps Inoperative
Park Lamps Inoperative
Step
Action
Value(s)
Yes
No

1
Inspect the PARK LP fuse.
Is the fuse open?
--
YES - Go to Step 2
NO - Go to Step 3

2
Repair a short to ground in CKT 1340.
Is the repair complete?
--
Go to Exterior Lights System Check
--

3
Turn the headlamp/instrument panel (IP) lamp dimmer switch to the PARK position.
Use a test light in order to backprobe the headlamp/IP lamp dimmer switch harness connector between terminal R and ground.
Did the test lamp light?
--
Go to Step 7
Go to Step 4

4
Use a test light in order to backprobe the headlamp/IP lamp dimmer switch harness connector between terminal O and ground.
Did the test lamp light?
--
Go to Step 5
Go to Step 6

5
Replace the headlamp/IP lamp dimmer switch. Refer to Headlamp Switch Replacement .
Is the repair complete?
--
Go to Exterior Lights System Check
--

6
Repair the following conditions in CKT 1340 between the PARK LP fuse and the headlamp and the IP lamp dimmer switch harness connector terminal O:
• A faulty connection
• An open circuit
Is the repair complete?
--
Go to Exterior Lights System Check
--

7
Repair the following conditions in CKT 9 between the headlamp and the IP lamp dimmer switch harness connector terminal R and S204:
• A faulty connection
• An open circuit
Is the repair complete?
--
Go to Exterior Lights System Check

Search Results

Tail - Running Light Testing - Professional Mechanics Online

www.2carpros.com/.../no-tail-lights-exterior-running-lights-tail-lights-ou...
Aug 1, 2015 - Begin with the car on level ground, engine off with the parking brake set, wear ... Step 10 - If all running or tail lights are not working, a fuse is used to ... light and test for twelve volts at the rear of the headlight switch connector ...

Park, Tail, Marker Lamps, and License
The park, tail and marker lamps, including the license lamps, turn on when the headlamp switch is placed in either the PARK or the HEAD position, or anytime the headlamps are requested. The RT I/P #1 fuse in the RH I/P fuse block supplies battery positive voltage to both the park lamp relay switch contacts and to the park lamp relay coil circuit. The park lamp relay coil is controlled by the body control module (BCM). When the headlamp switch is placed in the PARK position, the BCM energizes the park lamp relay coil control circuit.
Current flows from the park lamp relay switch to both front and rear park lamp fuses and to their respective park/tail lamps. The front park lamps are grounded at G101. The rear park lamps are grounded at G302. The license plate lamps are a part of the rear park lamp circuit and are grounded at G302. The inadvertent power control feature prevents the park lamps from remaining on more than 10 minutes if left on. If the park lamps are turned on after the ignition switch has been turned OFF, or is in the ACCY position, they will remain on until turned off or until the battery runs dead.

Did you the REAR PARK LP fuse 15 amp in the right insturment panel fuse box.

All the exterior lights run threw the turn signal switch. Except the high mount brake light. If you are talking about brake lights replace the TS switch. Parking lights are a little different. If you have no parking lights front and back, TS switch. If you have front and no back, ground problem. Grounds for the back are usually on the drivers side mounted to the frame.