Well, I'm asking this now, so when it comes time for me to come home, I'll have everything ready.

It hit me today while talking to my mechanic buddy, If what is going on with my truck, is what we think it is(electrical no doubt), then doing an engine rebuild would be pointless until the wiring is fixed, and further inspections can be done to ensure a rebuild-able block when the engine actually runs.

I have been searching, for a few hrs now, looking for a thread on the engine wire harness repair procedures. I don't have the massive ford shop manual for the truck, or access to a decent wire harness wiring diagram,(the layman can understand). (maybe i didn't right) However, I do have a nice diagram with the IDM connector wiring colors.

My theory is this:

Using thicker gauge wire, rebuild the wire harness(a wire at a time), using new connectors for most of the sensors where possible. New wire terminals, and soldered connections instead of rubber sealed splices in weird places that I assume came factory. As it stands right now, my engine wire harness is trashed. Rats nests, unbound wire, random wire with burn connectors, and lack there-of. Also, PO had replaced the VC harness more than once from the look of spliceable wire left when it came time to do mine, definitely a spot I want to fix.
Also, harness is missing convolute(cracked, rotted, just not there) in most places where it should be. I bought it like this, I just want it fixed!

Build theory:

I was thinking of running with 14GA wire for the build. Especially since the IDM wires flow a lot of juice. I think 14GA would give me ~15A capable wire, compared to the 10A from the stock wiring of 16GA(18(7A) in some places IIRC). An upgrade from my POV.

Has anyone attempted this procedure beyond basic wire replacement or adding to the existing harness? I realize this would require a lot of multicolored wire, labeling, solder, connectors, heat shrink heat wrap and convolute and TIME. But, since my truck isn't running ATM, I want to fix it before i think about stage 2's, HPOP, and E-fuel and engine overhaul, and still not get my truck to start.

Also it would beat paying IH or Ford 500$ for an upper engine wire harness! And this would allow me to fuse problem areas like the GRP, to minimize failure/replacement.

Any drawbacks to doing this? I understand the basic principles of wire, material, cross-sectional area, length, and temperature, in relation to resistance. But, will this affect or enhance the signal being sent or received ? Should some sensor wires stay ~18-16GA?

Also, a bigger engine fuse box from a newer truck(more spots). This would allow me more spots for accessories, and E-fuel wiring. I'm sure there is a write up on this somewhere, but would the fuse box be advisable or just leave it as-is? Should I rewire the fuse box with newer wire as well?


That's all I got. I appreciate any input, tales of caution or maybe a push in the direction I'm looking to go!

 

sounds like a lot of time an money
Probably cheaper an easier to buy a good harness.

 

Any other places other than junkyards?

 

Around here you can get a complete truck running sometimes for around $2000 or cheaper
I've scraped 4 or 5 and kept the harness's from them as spare's
And 1 for a short wide I'm going to build after I get my 4x4 dually done.
Got a new motor harness from ford for 350 and after that started keeping them

 

I was pricing wire, for 36$/100ft is not a bad deal, Maybe get 15' of a bunch of different colors, and connectors are pretty cheap too. I could probably save money just rebuilding it for that 350$ price tag!

Well, I'll still see what local ford dealer would want when I get back. There are no junk yards in ks have a 7.3. Even then, the engine harness might not be in that great of condition. I've tried just about salvage yard in ks. I would have to go all the way up to Nebraska 250 miles away just to get it, if they even had one.

 

Id like to know the name of your scrap yard you get your stuff from. The local guy I always went to went strictly to scrap metal.

Always hard to find good scrap yards for these old trucks. If you don't wanna share, that's cool too

 

Think you misunderstood what I said. I have bought Running truck's for that.
I have bought truck's an scraped them myself for part's. There's only a couple time's I've seen powerstroke truck's in the scrap yard. But when I do I take all I can from them before they crush them. Are you close to me? There's a few in Tulsa but I don't get to them much. I'm sure there are truck going through them. A buddy of mine just picked up a running driving 96 truck with a bad trans for under a 1000. He's pulling motor an trans for a car he wants to install it in. And I'm getting core support out of it and a few other part's. Guess it's just timing an luck around here

 

^X2

I can't seem to find any good salvage yards, and the ones I go to, are all newer trucks, if they have F350's they are all gassers.

 

Yes it's hard to find these truck's in scrap yard's because they are so GOOD an most are still running. I've found it's easier to find them on like craigslist with something wrong like bad trans or wrecked and buy them that way an scrap the rest. a month or so back there was 1 I almost bought in Kansas for 1200 96 I think dually 5 speed. But I had to many in the yard to get it. he ended up parting it out or someone else bought it an did because I see it again with motor and rearend out of it. there's a guy now with 8 trucks on cl for sale. 3 of them I know he got from cl because I called on 2 of them and they had sold before I called. I guess he don't want to mess with them now as he has them as a package deal for 8000.


3 F-450's 4 F-250's 2 F-350's a total of 9 trucks for one money

 

If you get to butchering that harness you had better solder and heat shrink every connection.IMO the biggest issue is every connection will still be old worn out pins.even with new wire you will have problems.then you have to think about the shielded wiring that there is to the injectors.this is not a small task IF you actually want it to run when you are done.
Quesey...how many harnesses DO you have lol?


I don't mean to be a Debbie downer but all things considered if I had a harness issue I would just cough up the jack.being broke down in timbuck too because of a 350$ harness may cost that 350$ to be towed in.

 

Dang, all I would want is the white dually. If for nothing but the body parts!

 

2 for sure 5 speed an 1 auto. But have other 's just motor harness's I think sold a couple. I went to ford right after I got my dually and instead of listening to people on here I bought a motor harness. Come to find out it was what everyone on here said it was
IPR fixed the problem
PM me if your needing 1


John

 

The only thing about that list of trucks for sale is only one is a guaranteed powerstroke. The 2 94's may be idi's.

 

Man am I hearing you! I had that drain back issue...rick saved me 700$ and a lot of heartache....20$ fix...I learn more everyday!! Quit learning...never ever!

 

That would be awesome! I have nowhere to have it shipped right now if I bought a 94-97 harness from you, but when I get back in the spring from this deployment, I'll definitely buy it off ya if it's still around! Where in Oklahoma are you? OKC is about 5hrs from where I'm stationed in KS. Depending on that, I could probably just drive and pick it up, and maybe visit a few junk yards there for some parts on the way back haha