5.0 stock / conversion harness question

stackz

Founding Member
Jun 13, 2001
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james island, sc
are there any how-to's etc out on the web for say how to take a stock 80's/90's 5.0 car's engine harness and cut out all the excess un-needed wiring, etc to make a toss-in efi harness for a project vehicle??

I've got access to a few lincoln's and thunderbirds with 5.0's in them and was wanting to rob one of the harnesses so I could make one for a project I'm working on.

Was kinda skeptical though as I see all this extra crap wiring going this way and that. There's gotta be a simple way to weed through it and end up with a simplified harness for my conversion, right?

also, if the harness came from an automatic car, I'd have to use it on an automatic conversion? or could I weed out the auto stuff and toss a manual ecu on it?

any info would be greatly appreciated. I don't mind the wiring aspects of it but I dont want to spend the $60 on a boneyard harness only to realize I cant do anything with it and I just dont have the $$$ to pay for a windsor-fox one.
 
Check out Windsor-Fox

I don't know about what you are trying to do, but the authority on the 5.0 EFI conversion for older Fords is Windsor-Fox.

Check 'em out at www.windsor-fox.com

They have a "No Brainer" wiring harness and will modify a harness for you. You answer a full page of questions i.e. Engine/Tranny/Computer serial numbers and all the accessories.

Jeannine is really nice and very knowledgeable. She typically answers the email questions.

Good Luck
 
i'm basically trying to save myself $400-700 dollars. I dont feel like paying that for a harness.

i dont mind racking my brain over getting the wiring right if I can get a boneyard harness for $25 and simply edit out the unwanted stuff. I've already found most of the info I need anyway so thanks guys.
 
ford motorsport also has a booklet itsin the catalog i think it sells for 5 bucksitshould be able to help. if i remember correctly there are a couple of wires that attach at the solenoid those are for the power obviously. the emissions crap you can cut out but would need a chip or a pms so the computer doesn't reference to them
 
What kind exact info are you looking for? I have always done my own harnesses and my current project is an EFI 5.0 in an 66 and I have already integrated the harnesses from the 2 cars. Your best bet is to get the wiring diagram for the car that was the donor for your EFI harness and use it as a reference....that is what I did. The engine control harnesses are usually separate from the main car harness and have very little extra stuff in them so you won't be removing too much.

The only difference between the auto and manual cars is the computer and the O2 sensor harness....which can be used for a manual, just use the wiring schematic to make sure everything is hooked up right because the color of the wires differs.
 
Ronstang said:
What kind exact info are you looking for? I have always done my own harnesses and my current project is an EFI 5.0 in an 66 and I have already integrated the harnesses from the 2 cars. Your best bet is to get the wiring diagram for the car that was the donor for your EFI harness and use it as a reference....that is what I did. The engine control harnesses are usually separate from the main car harness and have very little extra stuff in them so you won't be removing too much.

The only difference between the auto and manual cars is the computer and the O2 sensor harness....which can be used for a manual, just use the wiring schematic to make sure everything is hooked up right because the color of the wires differs.

ok, this is exactly what I was wondering mainly. I didn't know if there were any weird extra functions that were controlled by an automatic ecu or not that would be thrown off if all I found was a manual ecu and harness.

I found some diagrams online of the harnesses which have helped me determine they're pretty much self contained but I was still trying to figure out how I would tie the harness into the rest of the car's wiring? Like is it just getting a main ground, main power feed, and start signal to the rest of the car or are there several wires which need to be spliced in (say to the steering column, starter relay, etc).

I've got mitchel on demand and have all the wiring diagrams but I just wanna get most of the questions out of the way before I get started. research always helps something go faster and cheaper BEFORE you start a project I always say.