Retrofit an XJ overhead console for your MJ (tons of pics)

[Airborne Janitor]

Parts required from donor XJ:

 

Overhead console (OHC)

Sunvisors & clips (optional)

OHC wiring harness (runs along passenger A-pillar)

OHC mounting bracket & screw (only front most bracket required)

Temperature sensor (located behind front bumper, in front of "frame")

________

After scoring a couple of pre97 XJ overhead consoles (OHC) from the parts yard, I decided that one could be modified to work in the cab of an MJ. Figuring this project had been done before, I spent hours reading through threads on here and NAXJA. Some of the info and even FSM wiring diagrams didnt match what I had, and theres even different versions of the OHCs to make it even more confusing. So I started this thread to compile my notes and document my process. This is a long one so grab a beer and take a seat.

 

To start, I believe the pre97 XJ OHC was offered from 90-96. There are updated 97-01 OHCs that require OBD II to utilize all the extra computer features such as "average gas mileage" and "miles to empty". My documentation will deal with the older pre97 models.

 

OHC IDENTIFICATION

 

There are (at least) 2 different styles, and I do not know what year the break between them is. I had a 92 XJ Laredo years ago that had a "newer" style OHC for what its worth. The differences are the wiring for the lights. The "older" style OHC has 4 black wires that run from the front dome lights to the rear dome lights. The "newer" style OHC has 3 colored wires between the dome lights: black, yellow, and gray. The older style OHC is wired so that the rear dome lights would come on when the doors to the XJ were open, NOT the front lights. The newer style OHC has both front and rear dome lights come on with the doors open. Why does this matter? Because the OHC is too long to fit inside the cab of the MJ without being cut down, which means you have to get rid of the rear dome lights. If you have the older style OHC you will have to either rewire or swap the dome light fixtures if you want them to come on with the doors open. The newer style OHC you can simply cut the wiring to the rear domes and be done with it. Other minor differences between the 2 styles are that the older style has black covers over the bulb wiring, and removal of the covers shows a circuit board instead of the colored wires of the newer style OHC. Pics for reference, newer style on the left, older style on the right.

 

 

For simplicity purposes I chose to use the newer style OHC for my install. 

 

WIRING HARNESS

 

Let's switch gears for a moment and talk about the wiring harness for the OHC. In order to successfully do this swap you'll want to have the wiring harness that runs along the passenger side A-pillar.

 

 

There are quick disconnects at the kick panel and the wiring extends all the way to the roof and to the sunvisors. Also be sure to snag the temperature sensor behind the bumper. Theres a couple different styles of sensors but mine looks like this:

 

 

If you're planning on adding an OHC then swapping over to sunvisors with lighted vanity mirrors is an easy upgrade. From what I've seen the pigtails for the sunvisors are a single pink wire with a single thin, black connector, and never changed throughout all years of XJs. I have a nice set from a 98 XJ I am using, complete with airbag warnings. Whatever. 

 

 

Since I wired up 97 XJ power doors on my MJ, I wasnt going to make any attempt to wire up the keyless entry sensor/module, not to mention I didnt really want to open that can of worms. So I cut off the pigtails for the harness, which had black, green, tan, wires and a pink one on the OHC/keyless sensor end. The pink wire is spliced into the larger pink wire that powers the vanity mirrors so it has constant 12V power. I decided to crimp on an insulated quick disconnect to it in case I need easy access to power from the roof in the future. I'm thinking maybe wiring switches in the OHC eventually...

 

 

WIRING DIAGRAM

 

Here's where it gets confusing. There were (at least) 2 styles of wiring harnesses with completely different colored wires. I have seen several early 90s FSMs state the wiring for the harness is as follows:

 

Pink A - dome lamps (12v?)

Pink B - reading lamps (what's the difference?) 

Black/blue - temperature sensor

Violet/green - temperature sensor 

Orange/black - illumination (connects to the dimmer)

Blue/red - head lamps on (dims the display when the headlamps are on)

Black/blue - compass ground

White/pink - 12V 

 

Some individuals have stated they had a yellow wire that went to the doorjamb switch ground to activate the dome lights.

 

My wiring harness was different. here's how I wired mine:

 

CONNECTOR 1

Pink - constant 12V

Black - ground

Black/white - ground to doorjamb switch. The existing wire to the doorjamb switch was the same color, I simply spliced into it

 

CONNECTOR 2

Orange/green - temp sensor

Pink/blue - temp sensor

Black/orange - ground

White/black - ignition on 12V

Orange/black - illumination. I left this unplugged.

Blue - left unplugged. May be for headlights on 

 

 

If you did it right you should be able to plug in your OHC and sunvisors and have power.

 

 

 

 

 

[Airborne Janitor]

If you're pulling one of these from a junkyard rig chances are it's probably in rough shape, at least the upholstery probably is. You will also have to cut the OHC down to fit in the cab of the MJ, and rebuild/reshape it. So if you want an OHC done right you'll need the right tools and skills to make it work. Disassembly requires 3 tools really, a Philip's screwdriver for the dome light housing screws, and a flathead screwdriver and a small pick to undo the little plastic clips that hold the OHC together. But you'll need something to cut the console with precision, and something to rework/shape the console. I am using an electric cutoff tool (dremel could work too) and a plastic welder, I know some have used resin/fiberglass. 

 

OHC DISASSEMBLY 

 

There are 3 Philip's head screws for each dome light housing that needs to be removed. 1 small Philip's head screw to remove the keyless entry circuit board. After that its careful prying and manipulation with a flathead and pick to remove the OHC into multiple pieces: the shell, the sunglasses/garageopener/computer housing, the front computer/dome light assembly, rear dome light assembly. 

Take your time and be careful, the plastic may be brittle and not flex without cracking. Be especially careful when removing the main housing from the shell, start with freeing the rear housing tabs then working your way forward to computer. Then pull it down and away from the shell. don't try to force the computer parts out. Once you remove the housing it's easy to see how the computer assembly attaches and removes. Theres also a small plastic plug that sits where the front OHC screw goes through. I found using a pick and gently prying it out was the best way for removal without damage. Once the parts are free you should just have a shell and the upholstery should peel off easy. Scissors help too.

 

 

OHC CUT AND REWELD

 

Now for the fun part. Since the XJ OHC is too long for the cab of the MJ, it has to be cut down to fit. If you don't want to have a hacked off piece of plastic for the rear of your console, you'll need a way to shape it. If you're skilled with fiberglass that's an option. I'm not, but I do have a plastic welder...

 

 

My wife got it for me as a gift from amazon a few years back. I wanted it to repair the torn mounting tabs on the flares on my XJ. Since then I've used this kit for all types of projects, even fixing broken battery doors on remote controls.

 

First, I cut my OHC into 3 pieces using an electric cutoff tool. 

 

 

Then cut the rear piece down the middle since it was too narrow to fit properly.

 

 

I treated all the pieces as if I were dealing with welding steel, which meant beveling all the joints to allow a place for the filler to fuse. I used a dremel with a grinding wheel.

 

 

Tacking the pieces together...

 

 

Running beads...

 

 

Welding it all together then sanding it smooth. Note I did cut up 2 OHCs to do this. I planned on keeping one of them as a "parts donor".

 

 

Then more cutting with the cutoff tool to fit the contour of the headliner.

 

 

Picture of the inside of the console to show off the ugly (but strong) welds. After welding the outside (but before sanding) I used a dremel to quickly groove the inside joint then ran a plastic bead. 

 

 

I decided I wanted to reuse the rear "paddle" portion of the XJ OHC so that the fit of the modified MJ OHC would be tight against the headliner.

 

 

The plastic welder is generally used for butt joints, but a cool feature of this particular model is the use of a flexible steel mesh and a universal fiber flex plastic that can make all types of unconventional plastic repairs.

 

 

You basically melt the mesh into the base plastic, then melt the fiber flex on top of the mesh, essentially sandwiching the mesh. The repairs are very strong, as strong if not in some cases stronger than the base plastic. I used this method to essentially fillet weld the paddle mount to the MJ OHC. I just had hernia surgery (hence the free time to pursue this project) and I felt like the surgeon made a similar repair to me...

 

[Airborne Janitor]

INSTALLING XJ SUNVISORS

 

The MJ sunvisors are longer than the XJ ones, and will interfere with the installation of the OHC. However you will need to drill some holes to mount the XJ sunvisor retainer clips. I reinstalled the headliner and the XJ sunvisors, then snapped the retainer clips onto the sunvisors to mock up their place on the headliner. I used a hammer and punch to center punch all holes for accuracy. Removed the headliner then used a stencil, square, and scribe to mark the holes.

 

 

INSTALLING THE OHC BRACKET 

 

I took the following pic from the donor XJ I pulled the OHC out of. Proved to be a good reference for mounting the bracket. You did grab the mounting bracket for the OHC right?

 

 

Using the bracket itself as a template, I was able to mark all the hole locations. I basically eyeballed it with the above photo.

 

 

 

 

[fiatslug87]

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[Airborne Janitor]

 

MODIFYING THE HEADLINER

 

Of course your new OHC won't fit unless you're willing to cut some holes in your headliner. I drew as straight of a line I could down the middle of the headliner to use as a reference. 

 

 

I used tin snips and metal cutting shears to cut the holes. Thankfully everything looks good and the MJ OHC is a tight fit.

 

 

Now to get the MJ OHC and headliner reupholstered. Hope to drop them off at the upholstery shop tomorrow.

 

[Airborne Janitor]

A little sneak preview because I'm impatient. 

 

 

 

[ghetdjc320]

Looking awesome! These are the kind of mods I really like to see

[boxyjeep]

That came out amazingly good.  Awesome work!

[Airborne Janitor]

Thanks guys. I'm very pleased with how it's all turning out. 

 

HEADLINER REPAIR

 

So my headliner was in decent shape, but had a few splits and cracks. The upholstery shop I went to used basically chipboard and upholstery glue to reinforce those areas. Although the upholster was adamant that it wasnt chipboard because it was "oil and moisture resistant", I used chipboard I had on hand to reinforce a few more areas. I used Permatex headliner spray glue.

 

 

Next weekend I hope to be back at it. Waiting for some sound deadening material and LED bulbs to come in to wrap up the job.

[Airborne Janitor]

SOUNDPROOFING (OPTIONAL)

 

Figued while the headliner was out I'd put some soundproofing material on the roof. I already had applied a POR15-like roll-on to prevent any further surface rust. There are many options on the market nowadays for sound proofing/deadening material. I think Dynamat Xtreme is still supposed to be king. I've used it in my XJ with great results, but didnt really want to spend the money for it in the MJ (already far over budget). Did a little bit of homework and decided to use Kilmat this go around, seems to be extremely similar to Dynamat for a fraction of the price. Got it off amazon and it's made in Russia so be careful, application may cause foreign spying and election tampering 🙄🙄🙄🙄😀 

 

 

 

REINSTALL HEADLINER AND OHC

 

Before I installed everything I replaced the bulbs in the OHC, sunvisors, and courtesy (kick panel) lamps with LEDs. Onewaylight.com was having a going out of business sale so I took the opportunity to purchase a few of their kits. After that it's just popping the headliner back in place, then installing the sun visors and OHC. 

 

 

 

TEMPERATURE SENSOR

 

See the photos for installation location. I ran my wiring through the passenger headlamp and along the relay wiring on the passenger side of the engine bay.

 

 

I drilled a 9/16 hole and installed a grommet through the firewall under the blower motor then pulled my wire loom through.

 

 

I won't tell you it's the prettiest looking wiring (especially with my 97 power doors) but at least I can hide it behind the kick panel.

 

 

 

FINAL WRAP UP

 

Well if you did it right and all the equipment works correctly you should now have a functioning OHC. Its awesome having a dome light, compass, and thermometer. I have not tested the compass for functionality, I heard there is a way to calibrate it, maybe someone else can chime in? I was also able to reset the spring for the sunglasses holder so that functions as well. If you pay close attention you may notice there is a slight gap between the middle of the OHC and headliner. I tried to pad this area with more Kilmat to close the gap but was still left with about a 1/4" gap. Whatever, I'll use it to hide my drugs 😵😵😵😵😀

 

 

 

[Jeep Driver]

That's nice. 

[Pete M]

well done!  when you're ready, I'll move it over to the DIY forum and add it to the master list.  

[ghetdjc320]

Awesome work and great write up! If i ever head back stateside I’ll do this also. 

[CoastChief]

wow that looks so clean, awesome work!

[DIRT_NASTYY_]

This is awesome, I have been wanting to do this while redoing my interior. 

Where did you move the compass to when you chopped it down? Is it just hidden inside the console itself? 

 

[Minuit]

1 hour ago, DIRT_NASTYY_ said:

This is awesome, I have been wanting to do this while redoing my interior. 

Where did you move the compass to when you chopped it down? Is it just hidden inside the console itself? 

 

The compass is part of the same board as the display. It's all in the very front of the console.

[AZJeff]

That is a REALLY FIRST CLASS job of fitting that OHC into the MJ roof.

 

I had an XJ with that long console, and the one I have in my MJ now came with the vehicle (but not connected) and is the "mini" one, with only some map lights, and no thermometer/compass.   I like yours much better!