inside cab lighting

[jamespwsullivan]

I'm trying to fix my interior lights. I'm talking about the ones mounted high up behind the doors. These are the only interior lights other than the glove box and instrument cluster. There is power to the lights but they will not come on. I'm pretty sure that the issue is with the ground in the door jamb switch. If I'm right about this, when I attach my test light to a positive both sides (with the door open) should complete the circuit to ground and the light should come on.

 

If that's correct, where does the door jamb switch go to ground? I think I found its connection to the harness in the dash, but where it goes after that is anyone's guess.

 

Secondary question-I have a "complete" service manual on CD but I can't find any electrical schematics! Can anyone direct me to a source for those?

 

Any ideas are welcome. Thanks

[HOrnbrod]

I guess you know the light lens rock to three positions: OFF, ON w. DOOR, ON CONSTANT? Also turn your dimmer rheostat on the headlamp switch full ccw (or cw depending on what you have) to see if they come on.

[jamespwsullivan]

Yeah. I've done all of the easy trouble shooing i can think of. With the fixture out of the trim panel there is power on the pink wire when i ground the test light. The other two wires (both black w/ white) should be the ground and the pass through of the ground to the other light. Neither completes the circuit so I looked at the door jamb switch. it doesn't ground either.

[cruiser54]

Those lamps ground eventually at the overloaded instrument panel ground described in the following write-up.

 

BUT, there is a connector for them called a C118 under the left side of the instrument panel and behind the kick panel.

 

Improving the Instrument Panel Ground

 

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, Seatbelt and key warning, trans 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 have a 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.

 

**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.**

 

 

Revised 11-29-2011

[HOrnbrod]

It's probably the door jamb switch then as they do go bad often. Pull both and check to see if the make and break with your meter.

 

Here's the schematic for an 88 MJ. If it's too small to read shoot me your email address and I can send you the complete 88 electrical manual.

 

[jamespwsullivan]

You guys are the best! Since I'm doing this work in my driveway and it's going to rain all week, I'll post after I get this looked at over the weekend. I found the link to the download for that 1988 electrical manual so I have the ground plane as well.

It pays to spend some time in the forums.

[Grant]

I too have a problem with my lights. I just bought the euromtec replacements. they are nice. The hole where my door jamb switches screw in are both stripped, way to big. What do we do? pop rivit in a peice of sheetmetal and redrill the hole?

 

Thanks

 

Grant

[87MJTIM]

My issues are related to interior electrical.

 

My pwr windows don't work, but the power locks do.

 

My radio has power (keeps time and stores station presets), but no sound through speakers.

 

Pillar lights haven't worked in years.

 

Fan on heater/AC blower doesn't work. Temp adjuster works.

 

The factory equiped clock flickers off/on, especially when cold. Doesn't loose time.

 

I plan on stripping the interior this weekend and tracing wires.

 

Could this be just a grounding issue or will I open Pandora's box?

[cruiser54]

My issues are related to interior electrical.

 

My pwr windows don't work, but the power locks do.

 

My radio has power (keeps time and stores station presets), but no sound through speakers.

 

Pillar lights haven't worked in years.

 

Fan on heater/AC blower doesn't work. Temp adjuster works.

 

The factory equiped clock flickers off/on, especially when cold. Doesn't loose time.

 

I plan on stripping the interior this weekend and tracing wires.

 

Could this be just a grounding issue or will I open Pandora's box?

 

Did you see my post above regarding the instrument panel ground? That's a stone I wouldn't leave unturned considering the issues you've got.

[87MJTIM]

Did you see my post above regarding the instrument panel ground? That's a stone I wouldn't leave unturned considering the issues you've got.

 

I have it printed out. I wasn't sure if there was more I should be looking for.

[cruiser54]

Sometimes you have to make sure of what it ISN'T before you find out what it IS.