Get yourself a wiring diagram and slowly hack away what you need and dont need......It will either fall in line or you will throw it out and go buy a harness.....Really nothing to lose by trying.

In my experience with these things

You will need a wiring diagram so you will know what wires are power and grounds and which are the sensors or activators like for your injectors.
You will need to decide where you wish to mount the pcm also.

attach the harness to the motor and trans.
Mount the pcm where you wish it to be so you know how long the relocated wires need to be.

then you de-pin the wires from the computer block/plug - one wire at a time labelling them as "1" through whatever number of wires there are.
Making a diagram of the wiring block and where each wire came from. You may have well over 100 wires initially when you are done de-pinning. NOTE - you do not need to know what the individual wires are for while de-pinning  - the only thing that matters is that you number them, and mark them on your picture of the pcm plug where the exact numbered wire went.

You then remove all of the harness coverings, tape, loom , heat shields etc.

then you separate the wires from each other so that each sensor, and location, is now bundled by itself.

Any wires that didn't go anywhere from the harness to the motor accessories, switches, plugs etc, are likely not needed - do not throw out but do coil them up individually and set aside. These might be for heater, a/c etc as many manufacturers run that stuff through the engine harness rather than run separate harnesses. Also all of the original engine gauge wires will be here as you will not be using the factory gauges. there will be other non essentials like the low oil level sender. Keep in mind very few people have the skills to incorporate these "other" wires and such into a harness so decide early on that you are only doing the basic harness to make the engine run, and same for an automatic trans.

Now using your wiring diagram, and starting with any one sensor or plug - figure out which is power and ground. The remaining wires if any will be sensor related. You will need to figure out if the power wire is switched or constant power. If it is switched power - re install those wires to the pcm plug also - unless the wiring diagram shows them as external. It may also be switched grounds. AND  - some sensors do not have power or ground - just the sensor wires.

Now - for sure some wires will be too long and some will be too short when you are running the wires back to the relocated pcm. So cut, and shorten/extend as necessary - soldering and heat shrinking as you go.

Now continue to install the wires for the various sensor(s), switches, injectors etc, one unit at a time,  back into the pcm plug, and deal with the power and ground wires if present.

many circuits are ground activated - these definitely go back to the pcm.

And you do this with each sensor, or plug, or injector etc until you have all of the main wires plugged back into the pcm plug.
When you are done all of the various sensors and plugs you will have only a few wires left.

These are usually constant power to the 12v source, keyed power, fuel pump relay, and tach if there is one. These will be fused and or relayed as per your preference. My last harness needed two relays for electric fans, and one for the fuel pump. If you are not using electric fans you only need one relay. You will also have various ground wires coming from the pcm. these are best grounded to the motor.

Expect to spend about 20 hours doing your first one if you are good at wiring and reading manuals.
If you are a total noob at wiring - expect to be 40-50 hours.

This rewiring is exceptionally easy to do  - it just takes time, and a lot of patience,

Total cost - some tape, heat shrink, loom of various sizes and some terminals. Universal 2,4, 6, or 8 fuse blocks are available at most auto parts stores - so maybe $100 total

when you are all done you will have something that looks very much like the harness pictured in the above mentioned link.

I am sure I may have forgotten some little things  but the internet is your best friend and you can find anything if you look  - and you tube is amazing  - someone somewhere will have posted something to do with a similar project for sure.

good luck :)

-- Edited by Seeker1056 on Monday 5th of December 2016 01:15:05 PM

-- Edited by Seeker1056 on Monday 5th of December 2016 01:18:38 PM

-- Edited by Seeker1056 on Monday 5th of December 2016 01:23:50 PM

-- Edited by Seeker1056 on Monday 5th of December 2016 01:24:12 PM

-- Edited by Seeker1056 on Monday 5th of December 2016 01:28:29 PM

-- Edited by Seeker1056 on Monday 5th of December 2016 01:32:09 PM

-- Edited by Seeker1056 on Monday 5th of December 2016 03:15:52 PM

So I am at a standstill for wiring on this engine ....Fords are not as popular for the swap kits available lol....man imagine if it was a Mopar

So I found a guy that sells complete Chevy LS engines , bench tested, stripped down harnesses with Flashed ECM for around $1500 cdn
the engine I am considering is a 4.8 LS chevy from a 2005 truck
I know the ford guys will role over in their graves but man this seems like the best way to go

Anyone have thoughts?

I searched for a good running 302 but no luck...

Well I bought the 5.3 , however I mated it to a rebuilt 700R4 that I had.......now just making mounts for it and figuring out the TV cable setup!

 

do yourself a huge favour and buy the shift valve body kit that does away with the need to set up the TV cable - then it is only used as a kickdown for passing gear instead of regulating the line pressure

-- Edited by Seeker1056 on Saturday 15th of April 2017 07:18:12 PM