Has anyone done the 4.0l swap using a YJ harness? My jeep is a 89 YJ and my harness is a 92. From the looking at the bulkhead connectors there are like 6 wires that need modified on changing locations and that will make it plug right in. Can it be that easy???
I was looking to find the 5 wires needed to make the motor run but all i have is a blurry picture of a XJ bulkhead connector. Does anyone know whickh wires that would be on the YJ engine harness?
Steve...you are embarking on something that has made me nuts for a few weeks now. My swap is for a 01' motor in an 89' YJ and while this and other forums have helped me a bunch wiring info is very scattered and diverse. One post says a certain wire color while another says a completely different one. So far nothing is working for me and I'm starting to think the PO at some point changed the wires at the bulkhead connector for some reason. Maybe we can help each other out a little bit...I'm going to try again on my swap and will list all of the wires with color code coming out of my bulkhead connector to engine harness if you can do the same we can compare notes. Thanks in advance...Mitch
Steve - I did the 4.0 swap using a YJ harness. Had to change 1 wire at the firewall - my harness was for a Jeep with ABS - and I don't have it. This caused the starter to crank every time the brake lights came on......
What year was the jeep that got the motor installed into? I compared the bulkhead connector diagrams and i can see about 5 wires that are in diff spots from the 92 harness to the 89 bulkhead. I will be working on this today, any more imput on this will be great.
Let's get this done guys, your wiring may be a bit different because of the 01 engine harness is obd2. It has to be doable though.
the obd2 harness and ecu have provisions for extra sensors, usually an added o2 sensor at the minimum on the engine side. if you don't use the wires you'd throw a code but the vehicle would still run fine as long as the ecu wasn't trying to compensate for the code (e.g. adjusting afr due to the ecu being mapped with the missing o2 data). trying to mesh a yj ecu with a tj harness would be a nightmare. hopefully you're not doing that or vice versa. if so you will have a good understanding of how a vehicles computer system works when you're done!
any way, i wouldn't expect the 89/92 harness to be too different. the 92's had a different type of injection system but other than that much of it should be the same. as long as you have the newer ecu it should be pretty simple.
PIN PURPOSE COLOR STRIPE LOCATION COLOR STRIPE GAUGE
B5 Ground Black - Ground - - -
B4 Power from fuel pump relay Orange - PDC Dark Green White 14
C4 Coolant temp sender Violet - Remove from YJ
C5 Tach signal Green - Black PCM (Pin #A7) Grey - 18
F5 Oil pressure sender L.Green - Remove from YJ
D4 +12V to ignition switch Red - PDC Red - 12
D5 +12V from ignition switch during "start/run" Yellow - PDC and C107-10 Dark Blue White 18
G5 Starter, sends +12V from the ignition to the starter Green - PDC Yellow Red 18
E4 Battery power to lamps, etc Red White PDC Red White 14
F4 Heater blower motor Orange White Original location (blower motor) - - -
G6 Reverse switch Brown White TRS Brown L.Green 18
wires below not spliced
A7 Brake Sensor Grey Black Proportioning valve - - -
B6 Brake Sensor Grey Black Proportioning valve - - -
E5 Underhood lamp Pink Black Original location (underhood lamp) - - -
G4 Battery power for rear defog Red - - - - -
C6 Unknown Yellow Black -
I got the old motor mounts cut off, engine tranny and transfercase bolted together. I will be putting it in and welding in the new motor mounts to the frame tomorrow. I will have to pull it back out to install new tranny seals and transfercase seals that the stupid parts place did not stock.
Hi, I'm new here and I found your post in a search and was wondering how everything turned out. Are you done with the entire swap yet? Any glitches with the wiring? That's my main concern, as I'm getting ready to do a swap into my 87 Wrangler. I bought an entire running 1991 Cherokee with an engine that was rebuilt 5k ago and the tranny (5 speed) rebuilt 10k ago. I was thinking to swap the entire thing over - engine back to tranny. So I was searching and your thread seemed to be the closest to what I was doing. Thanks.
On my swap i used a wrangler harness , i switched some pins around on the 92 bulkhead connector to match the 89 bulkhead connector. You will be using the xj harness which is no where close, basically you will splice half a dozen wires into the 87 engine harness.
My swap runs great and i hope to finish mine completely this weekend.