I've posted on this swap before, but thought I'd try again now that all I have left is the wiring. I am swapping a 4.0 engine from a 1992 Cherokee into a 1980 cj7.

I've googled the crap out of it, but can't come up with anything specific.

I know I need the "5 to fire" wires, I have diagrams and can locate the wires I need from both vehicles.

The problem I am having is what do I do with these 5 wires exactly? I know that sounds stupid and elementary, but I am a complete novice.

Can anyone explain the physical step by step procedure for wiring up this swap?

I've asked on jeep forum and others but they're mostly jerks About it and just tell me to use the search function, which I have done for hours on end and cannot find any step by step on the actual physical steps of where and how to splice the wires or which fuse block to use or how to thin out what I don't need, etc.

Any help at all is greatly appreciated. I know it isn't a jeep forum but I figured good Ags might be able to help.

Also, if anyone knows someone in the dfw area that I could take my harnesses to that can help, that'd be awesome.

Thanks for that. I've been able to locate those wires but I'm not sure about the actual physical process of what to do with them.

I know that sounds really stupid but that's where I am.

Cut and splice them.

Haha, that's what I'm asking. How do I do that?

Cut where? Splice where? Connect where?

Youll need to connect the items from the engine itself to the engine computer.

I know to connect all the sensors, etc to the engine, but where do I cut and splice the 5 to fire wires?
Do I use the fuse block or bulkhead from the cj and the 4.0?

I am very very confused

an 88/89 YJ is not the same as a 80 CJ or a 90s XJ.

This is what you should do... clean up the harness for the CJ to remove anything that touched the engine other than gauge sending unit wires and the 12V ignition feed. starter wire too if you are using a 4.0 starter and not the 258 starter.

Clean up the 4.0 harness so that you've identified the 12V constant, ground, and switched 12V (This should be coming off of what Chrysler calls the "autoshutdown relay", its a fancy name for something that doesn't do anything that unique)

wire the ASD relay to what used to switch in the ignition module, hook up the 12V wire and you'll be good. The YJ harness had a relay and fuse bank that would be good to keep. The fuel pump relay goes there too.



[This message has been edited by robertf03 (edited 1/8/2013 7:40p).]

you shouldn't need this, unless you've butchered the harness badly




see splice s121?



thats where your old ignition module power goes. Make sure its hot in run and start key positions. The motorcraft ICM had one that was hot in both positions and one that was only on in start.

this one shows where the battery plays out in this mess



[This message has been edited by robertf03 (edited 1/8/2013 7:51p).]

Wow, thanks! That is helpful

no problem.

What transmission are you going to use?

The automatic. Tf999

did you modify the bellhousing, go to a later transmission, or move the crank sensor?

I'm ordering the cps relocator from hesco.

nice. sounds like a well thought out swap

I had some problems keeping the original accessories on my 4.0 swap. There was a constant error for the field circuit in the alternator. I don't think it triggered the check engine light, but my DRB II scan tool always showed it as flagged.

[This message has been edited by robertf03 (edited 1/9/2013 9:14p).]

So what did you end up doing? I know I'll encounter some of these little problems and will have to troubleshoot a little.

My last resort is to purchase te harness for this conversion from hesco. But it's kind of expensive.

wiring is the part of the swap im fearing. About to start a v8 swap into my 98 TJ. Just ordered all the parts from novak