Neverending wiring issues...

[SIERRA051]

I lost my instrument gauge cluster lights. Still have all exterior lights, turn signal and high beam indicators. It's not the fuse. It flickers on and off sometimes. Mostly stays off. Leads me to believe it is a grounding or loose wire problem. Any suggestions? I'm not sure where to start. Can't find what wire should control those lights. 

[Billy]

Just asking to get it out of the way but have you made sure to turn your light knob?  Same one that dims your dash lights, thought I had the same lightning issue and figured out my knob was just turned off.  

[SIERRA051]

Yup. I wish it was a simple fix

[Minuit]

Manual or automatic transmission?

 

While we're at it, fill out your signature with year, engine, and transmission at the very least. We can't help if we have no idea what you're driving.

[tugalo]

Sounds like a bad ground at the rear of the truck.  Remember, the instrument panel lights are designed to go off if there is trouble in the rear lighting that you can't see when you are driving..

[Gene]

When this happened to me it was the light switch itself. If ALL the dash lights are out this would be more likely, if some work not so.

 

If you really play with the switch can you get the lights to come on even briefly? That would implicate the switch.

 

Gene

[87MJTIM]

There’s a 5 amp fuse in the box- INST DSP. check that. You did say the lights flash. It maybe loose. 

 

Check the ground wire- G102 - under the dash panel. 

 

Go to Cruiser’s Renix upgrades to perform ground improvements

[Ωhm]

6 hours ago, tugalo said:

Remember, the instrument panel lights are designed to go off if there is trouble in the rear lighting that you can't see when you are driving.

 

Any insight as to how that works exactly?

[DirtyComanche]

13 hours ago, tugalo said:

Sounds like a bad ground at the rear of the truck.  Remember, the instrument panel lights are designed to go off if there is trouble in the rear lighting that you can't see when you are driving..

 

Wut?

[DirtyComanche]

12 hours ago, Gene said:

When this happened to me it was the light switch itself. If ALL the dash lights are out this would be more likely, if some work not so.

 

If you really play with the switch can you get the lights to come on even briefly? That would implicate the switch.

 

Gene

 

I'm thinking this was the most solid advice in the thread.  The switch is a bit of an overly complicated piece, and probably 30 years old, or it's a lowest bidder aftermarket version.  Lots of times its the contact for the rheostat in it, or the rheostat itself.

 

Personally I've had half a dozen or more go out on me...   But I normally grab them from the junkyard, so you get what you get.  You can clean them up and carefully adjust the contact to fix them sometimes.

[cruiser54]

21 hours ago, 87MJTIM said:

There’s a 5 amp fuse in the box- INST DSP. check that. You did say the lights flash. It maybe loose. 

 

Check the ground wire- G102 - under the dash panel. 

 

Go to Cruiser’s Renix upgrades to perform ground improvements

The ground point for the complete instrument cluster on your XJ or MJ is located up under the driver’s side dash. If you lay on your back and look up under there with a flashlight, without wearing a hat, you will see a black wire attached to a shiny piece of metal almost directly above the hood release knob. The screw will have either a ¼” or 5/16″ head on it.

This ground point is responsible for handling the ground circuit for the following items: Dome lamps, seat belt and key warnings, transmission power/comfort switch, wiper switch, headlamp switch and delay module, fog lamp switch, cargo lamp switch, all instrument panel grounds and illumination, power windows and door locks, cruise control dump valve, and a few more things.

The problem is that where the ground point is located does not share good contact with the chassis where the ground should be. The solution is simple:

• Make up a jumper wire with #10 gauge wire about 10″ long. On one end, crimp on a ¼” round wire terminal. On the other end, crimp on a 3/8″ round wire terminal.
•  
• Remove the screw from the existing ground wire and attach the small terminal of your jumper so that the original wire and your new jumper share the same attaching point, one over the other.
•  
• Look above the driver’s side plastic kick panel just forward of the top of the hood release knob. You will see an 8mm stud there. Attach the large terminal end there with a washer and nut over it tightened securely. Use a coating of OxGard at all ground contact surfaces when attaching the screw and nut.

**Special note for Comanche owners: Make your jumper wire 12″ long and attach it on the driver’s side kick panel close to the fusebox on the 8mm stud.**

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[Ωhm]

IP cluster, along with many other things, have two points for ground (G102 & G103).

[JMO413]

I had the same issue. I replaced the headlight switch and that didn't help.The wire from the headlight switch is orange with a black tracer. My turn signal indicators worked along with the bright indicator. It took me forever but I found a break in the orange wire finally. I added the extra ground also and that made them noticeably brighter.