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5.8 engine harness

As far as I know a 5.0L harness is the same as a 5.8L from the same vintage. Just make sure your injector connector style, ignition system (TFI vs EDIS), EFI style (MAF vs SD), and emissions components (EGR) match the harness.
 
welndmn said:
The 351 in the 87+ bronco has the engine harness tied into the body harness, I never saw a stand alone harness for that.
Are you an an emissions area?
Most people just use the Mustang 5.0 harness and swap to mass air.
Click to expand...
I am not in an emissions area, so no issues with that.

I pulled the 5.8 from a F250, and I pulled the whole truck harness with it. The problem is the harness is over 30 years old and very brittle. The engine harness is combined into the whole harness, but it can be separated and the rest of the body harness eliminated. However, as brittle as the pile of wire is, splitting the harness without damaging it is a challenge and it doesnt address future wire issues resulting from aged wire and brittle connectors.

The engine is in a 72 EB and I have a Ron Francis kit for the EB that I havent installed yet. But I bought that kit back when I had the original 302 in it, so the kit doesnt include the EFI stuff. Current plan is to run a stand-alone engine harness and a separate RF body harness.

Swapping to mass air will require tracking down the 5.0 intake. I was hoping to keep it density to keep the truck intake. Kinda stupid cause I had a 5.0 intake at one time and traded it off for something I dont remember and probably dont have anymore. Just the way it goes I guess.
 
So you are SD 351. Im assuming youre not using the emissions system. What year is your harness, and what ECU are you using? Because that will help narrow down what harnesses will work with your engine/bronco. The SD 302 & 351 harnesses from the F-series should both work with just a bunch of plugs unplugged depending on which one you use. Some of them are built differently though, in regards to how they connect to the firewall harness; 87-88, 89-92 IIRC, there was another change around 94, and the OBD-II stuff is different as well. But, as far as the EEC-IV stuff goes, theyre still all pinned the same at the ECU connector so really you can use just about whatever one you want with some minor work.
 
pretty sure it was a '90. I pulled all this stuff like 15 years ago, so ... memory. I would have to find the ECU to know which one it is, in a box somewhere on my barn loft, but sounds like that is less of an issue.

I didnt realize there were so many detail-y changes along the way. Guess I should have, ... oh well. Durn. I was hopin to no have to split the old harness.
 
It's mostly minor stuff. Ford moved connectors around in an effort to clean up the wiring under the hood. All the EEC-IV engines use the same sensors with connectors (the exception being the 460 TPS) so really just about any harness will work with a little effort. But if you want to use an OEM engine harness with an OEM under hood harness you're best bet is using the same model year. It gets weird with bronco vs pickup too because even though the ECM 60-pin connector is pinned the same the round bulkhead connector isn't pinned the same between the two. Not just bronco tailgate stuff but all sorts of wires in different locations in that connector.


Those harnesses you linked from Painless are for mass-air vehicles which means sequential injection. Your best bet will probably be to just use an old harness because I'm not sure of anyone who makes a SD batch-fire harness. You could use the mass-air harness, but it would be just as much work to rewire to use that vs an old junkyard harness.


But since we're talking motor swap in an EB and all you need is an engine harness, I'd get pretty much any 87-94 harness you find in good shape and open it up. Remove the emissions sensors, drop the knock sensor (if its a harness from a 302) and lay the wires out the way you want em. Been there done that, and Its not as terrible to do as it sounds.
 
reptillikus said:
But since we're talking motor swap in an EB and all you need is an engine harness, I'd get pretty much any 87-94 harness you find in good shape and open it up. Remove the emissions sensors, drop the knock sensor (if its a harness from a 302) and lay the wires out the way you want em. Been there done that, and Its not as terrible to do as it sounds.
Click to expand...

Thanks for the suggestions and guidance. Very helpful. :beer: I get your suggestion of pulling a harness to use. I have struggled with too many old harnesses to get them working. Broken conductors, etc. 87-94 puts it at ~30+ years old. That leaves me in the territory of is it not running because mechanical or wiring? Hoping to rule out the harness. But I get what you are laying down. I need to go dig out the harness I have and start cutting it out of the body harness and checking continuities. sigh.
 
Ive been down this road. Took the body off my 88 bronco and swapped it for a p/u cab. Later put a 460 in. Then recently went back to a bronco body. So ive had my harness stripped down to its basics several times at this point. It can suck if its an unknown year or model harness. Ford used mechanical crimps smothered in rubber for their 5v reference and for their sensor grounds, so i def recommend breaking down the harness to inspect the crimps, and eliminating anything you dont need, if only to simplify it. Ford also made minor changes to their color code and wiring layout from year to year, so you really need to know the model year for the harness if you want to reference the EVTMs. I have the 88, 89, 92 & 96 EVTMs because of this.

So- Ford's connectors are called Wedgelocks. You can get brand new pins on the interwebs, and they use the same crimper as the generic Weatherpack connectors do. The plastic plugs are easy to disassemble once you know how, and while i dont have a source for new plugs, there's still lots of them in the junkyards so its really not all that hard to run new wires and use junkyard plugs. Ive scrapped a few Fords over the years, and saved the harness out of a few of them so id have 'spare parts' for repairing the harnesses in my trucks.
 
clodhopper said:
I pulled the 5.8 from a F250, and I pulled the whole truck harness with it.
The engine is in a 72 EB.
Current plan is to run a stand-alone engine harness and a separate RF body harness.

Swapping to mass air will require tracking down the 5.0 intake. I was hoping to keep it density to keep the truck intake.
Click to expand...

The truck intake doesn't fit well under an early bronco hood at all. Having the throttle body high in the front is the worse spot. The BC Broncos adapter from a 5.0ho upper to truck 5.8l lower is the cheapest way to go and then buy a fresh mustang efi harness. It will run better, fit better, and be more reliable.
 
Was planning to cut the hood.... but I probably have been watching too much Roadkill lately.


Kinda kicking myself for trading away the mustang intake I had. :shaking: But my buddy has actually been using it while mine has been sitting half built for way too long. Sigh.
 
I've got a few harnesses around here. Most are mass air. Some have been reworked, some are virgin. I'm on the plains now too.
Personally, I'd do the Mass air swap and shorter intake. But, I've also got a hood that has been cut for a scoop. PM me if you are interested.
 
I run lightning lower intake but they are getting expensive. There is a cast version that is cheaper. i think trick flow has an intake That works. I run 2” body lift to clear.
 
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