2003 TJ lighting Issue

[Lorne Shears]

Having lighting issue on my 2003 Jeep TJ.
When driving:
(Rear) I have no lights illuminated, unless I have the turn signal, hazard, or depress the brake pedal.

(Front & Sides) The headlights & fog lights work fine, but the turn signal lights only illuminate when the turn signal is activated. Side marker lights also only work when turn signal is activated.

During night driving, nothing is illuminated except the headlights and fog lights, unless a turn, hazard, or brake command is activated.

I've replaced all bulbs, the multi-function turn signal switch, the wire harness that plugs into the back of the multi-function switch, the turn signal relay, and verified all the fuses with ohm tester.

Any suggestions?

 

[Chris]

Could be a bad ground. You aren't using LED lights I assume?

 

[Lorne Shears]

If it was a ground issue, the non-working lights, shouldn't flash during turn signal, hazard, and brake sequence. Correct?

 

[Lorne Shears]

No to LED lights

 

[Steel City 06]

It sounds like something is bad in the running lights (or parking lights) circuit. This circuit should light up the taillights, sidemarkers, front fender lights, and interior dash lights.

LEDs won't cause this kind of issues unless installed in the sidemarker locations.

Could be a bad multifunction switch or a loose wire somewhere.

Could even be as simple as a blown fuse. Check the fuses behind the glovebox and in the PDC, particularly any one labeled "running" or "parking" lights.
In this example it would be fuse #1 behind the glovebox:

Best source for wiring information will be the factory service manual, available here:
https://wranglertjforum.com/threads...ice-manuals-fsm-technical-documentation.4618/
Download your manual, scroll down to the wiring diagrams, and it should tell you where all the splices and components are to check.

 

[Blondie70]

I was having weird lighting problems and the new multifunction switch fixed 'em all.

 

[Lorne Shears]

All fuses (engine bay & behind glove box) check good. I've replaced the multi-function switch 2 times already, with new ones from Napa.
Still same issue.

 

[mrblaine]

Having lighting issue on my 2003 Jeep TJ.
When driving:
(Rear) I have no lights illuminated, unless I have the turn signal, hazard, or depress the brake pedal.

(Front & Sides) The headlights & fog lights work fine, but the turn signal lights only illuminate when the turn signal is activated. Side marker lights also only work when turn signal is activated.

During night driving, nothing is illuminated except the headlights and fog lights, unless a turn, hazard, or brake command is activated.

I've replaced all bulbs, the multi-function turn signal switch, the wire harness that plugs into the back of the multi-function switch, the turn signal relay, and verified all the fuses with ohm tester.

Any suggestions?

Check the tail light bulbs. I've seen similar issues when someone forced 1156 bulbs into the 1157 sockets. That and check your grounds. The reason that grounds need to be checked is Jeep switches some of the grounds to make the various lights do specific things and not all of them are straight conventional + and - to make them work.

 

[Lorne Shears]

Thanks
I already changed all the bulbs with correct new ones.
I've checked every ground connection, that I could find. Still same results.
I know it's going to be a ground issue. I just wish I knew for certain where the ground connection would be located that would effect, front, side, and rear markers would be at.
All these lights work, when using the flasher, turn and brake functions, just not the night time driving situation without a flashing function.

 

[mrblaine]

Thanks
I already changed all the bulbs with correct new ones.
I've checked every ground connection, that I could find. Still same results.
I know it's going to be a ground issue. I just wish I knew for certain where the ground connection would be located that would effect, front, side, and rear markers would be at.
All these lights work, when using the flasher, turn and brake functions, just not the night time driving situation without a flashing function.

I'd start with the two that attach to the grill on the back side near the headlight buckets.

 

[Steve Boat]

My Tail Light Project