I'm looking to build a custom harness for my 88. The factory one finally gave out on me this spring and I haven't been able to get it running since. I have had no start gremils for years (thanks a lot Renix) and I'm ready to try and simplify as much as possible.

I built my own fuse panel to run the basic few things this Jeep still has but I would like to eliminate the factory harness completely if that's possible.

I have an aw4 but I have bypassed the TCU and my transmission is actuated via dash switches.

This xj is nearing trailer queen status so I'm not concerned with keeping it "stock". That ship sailed many years ago.

 

Painless Performance can probably provide what you need to get started so you don't have to reinvent the wheel.

 

So I decided to go the diy route. I built a custom harness with just the bare bones items to run and nothing else. I thought about a painless kit til I saw the price and realized I could do that myself for free. I took the harness out of my wifes MJ since its getting swapped anyway. I'm currently running a 90 MJ manual ECU with all the 88 electronics. This is all thats required to make these engines run
CPS
TPS
Cam sensor(sync sensor)
MAP
Coil
Injectors
ASD relay (Latch)
Fuel Pump Relay
IAC (Air Stepper Motor)
CTS
IAT
Knock sensor (not critical)
o2 sensor (not critical)

Here are the resources I used along with a FSM to build this harness.

http://www.pirate4x4.com/forum/jeep-...e-harness.html

http://jeep.zerok.ru/index.php?page=124 (scroll down)

It took me about 6 hours to tear down and I have about 10 hours on rebuild and install. I have a small fuel leak on my fuel cell but it runs again. I'm in the process building the inside harness now and getting everything tied together properly but it should be up and running by next weekend. Also, don't forget that I have also bypassed the TCU for the AW4 so if you will need to eliminate that harness and work out switching gears if you have an auto. If anyone wants to tackle this project feel free to PM me. Its really not as bad as it seems.



The pile I started with




New harness installed prior to triming




Driver side Trimmed and wired.




What was deleted from the factory harness




Harness done.