97+ Wiring Swap HELP

[simmonsm]

Hey, this is Mark, I have been converting my 87' Sportruck to a 1999 and have finally got to the wiring. I have a couple of questions to the guys who have done this project before or are doing it now. First, since the XJ harness has splits into two harnesses for the tail lights and the MJ is one up untill the rear bumper, would I just cut say the XJs passenger side tail light harness and only use the driver's side to mate to the MJs?

 

 

Also, I have the pigtail for the MJ which only has four wires (I removed the fuel pump lines) which are BLUE, BROWN, BROWN/WHITE, and GREY/BLACK.

 

Now, all that I need to know is which wires from the MJ will cordinate to those ;of the XJ which hase eight wires, BROWN/WHITE, GREEN/RED, BROWN/GREEN, BLACK, WHITE/TAUPE, BROWN/YELLOW,BROWN/RED, and RED/ORANGE

Of these eight wires on the XJs female three terminate and don't crossover to the XJs male, is there any reason for this?

 

All this for these two plugs to fit each other

[simmonsm]

When I put the ground from the driver's tail light area to the mj male plug it will be five wires from the mj to five wires to the xj, Any suggestions on better ways to do this I'm open ears, I can maybe clarify if no one understands this..... :nuts:

[Backdraft]

Mark, I would say your best bet is to wait until you get your XJ harness in the truck and wait on the tail/brake/turn lights until the front wiring is squared away. Just a suggestion, but what I did was get all the wiring plugged in and hooked up from the dash forward then plugged that particular body harness in where it needs to be. Drop a battery in it and use a test light to "tone" your particular wires out. For example, mash the brake pedal and check to see which wire gets "hot", then turn signals, running lights, backup lights, etc.

This is the most confusing part of the wiring IMHO simply because Jeep didn't use standard colors from year to year on the wiring. Personally, I used the wires on the drivers side to power the running lights, brake lights, backup lights, and left turn. Then I reran the right turn from the passenger side over. Used a test light to figure out which ones were what. Then toned out which wires did what on the MJs rear harness by running a power wire from the battery into the cab and probed the pins in that plug. Once that is narrowed down, use the plug from the MJ and splice/solder your XJ wires to it, then just simply plug it in to the MJ rear harness plug! Hope that helps! :cheers:

[simmonsm]

Thanks Mike, that sounds like a good idea. I will eventually wire the lights like you mentioned, but for the time being I rigged the xj plugs into the mj tail lights so all that I will have to do is lengthen the XJ harness.

[Backdraft]

Great! Glad you got it handled.

[Rymanrph]

I chose to keep two separate harnesses and ran them both down each side of the truck to the tails. I have the connectors on the frame rail so that If I ever need to remove the bed, all I have to do is unplug each harness without having to remove the tail lights. I have a wiring diagram for mine that I've posted, but I'm not sure if the wiring changed between 97 and 99. The easiest way for me to figure it out was to mark which wires went to which light on the XJ as I unplugged them and then just matched them back up to the MJ pigtails. You'll have some common grounds that you'll have to sort out, but its not very difficult.

[knkn9]

I'm having the same problem now, I'm stuck in this, for the guys that have done this, do you have any picture?