Rebuilding engine wiring harness

[13fist]

Finally decided to deal with old connectors, aged wires, and ratty looking tape & loom.

This one from the alternator has been bothering me since I got the truck. The green rot goes back several inches.

While I've been collecting pigtails, wire, and fresh bits & pieces I was doing a lot of searching for diagrams, pin-outs, and what not. Everywhere I've read has said this main wire from the alt cannot be replaced.
Turns out that is not at all true. Since I was replacing worn out GPCM connectors, I was going to have to deal with it anyway.

At least on my truck this is the only place in the wiring harness where this cable ties into anything. While I'm sure GPR truck are different, I can't imagine it being more complicated.

Once it was de-pinned from the connectors, it was completely free from the harness. Trading it for a run of 2ga and a mega fuse to replace the fuse links, and this was the easiest part. Still got ICP, IPR, & Valve cover connectors to do.
I was originally going to finish everything up in cheap techflex split braid I got from amazon. It will work for some of it, but I didn't pay attention to the heat rating and it does get melty in places where it contacts hot engine. Gonna have to rethink that.
This mess is a more time consuming job than I expected, but I should have it wrapped up later today and have more pics.

 

[lincolnlocker]

Good thread man! It would be good to see how you replaced everything. Take lots of pics for a how to post. Im sure lots of guys want to do this.

live life full throttle

 

[13fist]

Yeah so it's decided to rain all day. Progress isn't what I had hoped for, but Managed to get a lot done anyway. Pretty much all that's left is ICP & IPR pigtails, then organizing and wrapping things up. Probably Monday before I get to it again.
I did plug everything back in an take it for a drive to make sure I hadn't messed anything up. Luckily no smoke, sparks, fires, or check engine light.

I must insist on a measure of leniency for the following images. Weather and needing this running for tomorrow, everything is temporary. Better details and pics will come....

Huge mess right now :shocked: LOL. This is a completely unwrapped wiring harness with everything separated. Don't worry, it's not staying like this.

This is the good stuff though,

2ga cable to alternator, 2ga buttsplice with the gpcm connection crammed in and chock full of solder. Wrapped in adhesive heat shrink tubing. I'm still somewhat amazed the number of discussions I've read stating this cannot be done. Surely I can't be the first 7.3 guy to go there.

2ga cable runs along above the valve cover to the alt, then back down the the driver side battery.

protected by 250amp mega fuse. Although not originally planned this way, I do like the fuse location. Might make this permanent.

Over on the passenger side, I just ran the wire from the solenoid to the battery terminal over there.
AIH relay, bowl heater, water in fuel, and a slew of other things no longer on my truck got de pinned from the 42 pin connector. I never liked having the wires flopping around for nothing.
Over all this is not hard to do. Just very time consuming doing one wire at a time, checking continuity & resistance, and making sure nothing get tangled or spliced to the wrong thing.

A good heat gun, soldering iron, smallish butane or propane torch, and top shelf wire strippers are about all of whats needed for tooling.

More to come.

 

[lincolnlocker]

Dam. Looks good to me. Im sure someone would appreciate this thread.

live life full throttle

 

[mikes02ls1]

Nice.


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[Arisley]

I have heard many times about things not being able to be rebuilt. My Dad tought me something many, many years ago. If it was built by man, another man can tear it up, and yet another man can rebuild it.

 

[lincolnlocker]

I have heard many times about things not being able to be rebuilt. My Dad tought me something many, many years ago. If it was built by man, another man can tear it up, and yet another man can rebuild it.

So very true!!

live life full throttle

 

[13fist]

Got a fortunate break in the weather. I managed to get 99.9% done. All that's left is the last of the covering. Looks like I'll have to spend on the good stuff, probably Painless loom. I've used it in the past with great results.

The 42 pin connector. It's super easy to work with.

Use a little screw driver to lift out the red retainers. Make sure to re-install them when done. They prevent the terminals from backing out.

Once the retainer is out. Carefully pry the tab away from the connection of choice. It will easily slide out the back. This was a hard pic to take.

Here's the terminal shot. Ford Wedgelock Terminals E7EB-14487-AA for the engine side of the 42 pin, E7EB-14461-BA for the chassis side. If you have damage to your wires and need to replace a whole run from the connector. These are a crimp-on affair.

Code eliminators, shortened and tucked away.

These are the 1watt 470 Ohm resistors for the something or nuther I removed years ago. I think it was the EBPV and the waste gate controller... I think.

Used some of the heatshrink to seal them. This will keep corrosion out and make for a proper headache should I need to replace them.

Front of engine stuff,

CPS,EBP, coolant temp, oil pressure all consolidated into their own bundle and branched out from the 42 pin along the driver-side and across the front as seen here.

Still working on a good shot of the valley. Not a photographer.

It's still a mess with the bulk of the glow plug and injector wires unwrapped.

This is where I'm liking it. Forward up and over where the bowl used to be. The connections to the valve cover gaskets lay down nicely going forward, and out of the way.

I didn't get any pics of the valve cover connector replacement. It was about as straight forward as it gets though. I kept busy with one wire at a time so as not to mix up firing order.

Now for some part numbers: Use your reliable source of choice to ensure you don't get buggy import parts. These aint cheap, but this is not the place to skimp. Still costs a lot less than a fire under the hood, or a roasted PCM or IDM.

IPR / VGT / EBPV Soleniod Pigtail Connector Repair Kit 94-07
Part Number:
6E7Z12A690DA
Valve Cover Gasket Connector Pigtail 99-03
Part Number:
AP0016
GPCM Wiring Replacement Pigtail 99-07
Part Number:
4C3Z12B568AA
CPS Harness Pigtail 94-03
Part Number:
7U2Z14S411SA
Engine Oil / Coolant Temperature Sensor Pigtail 94-03
Part Number:
3U2Z14S411HYB
ICP / EBP Pigtail Harness 94-07
Part Number:
5C3Z12224A

Any questions, criticisms, advice, or tasteless humor, please feel free to do so.
Anyone with a GPR truck wanting to add to this would be most welcome.

 

[lincolnlocker]

Dang man! Looks good!

live life full throttle

 

[13fist]

thanks man. It was tedious, but worth it.

 

[toybreaker]

Had an "ozone" plastic smell last weekend, raised the hood and the power lead on the GPR was glowing red.... Looks like I am going to need this thread.... Thanks!

 

[13fist]

Had an "ozone" plastic smell last weekend, raised the hood and the power lead on the GPR was glowing red.... Looks like I am going to need this thread.... Thanks!

Dang! what was the cause? Did the GPR get stuck closed?

I hope you can find it helpful.
If at all possible could you post pics of what you do. It would be a benefit to the thread if GPR differences were included. Also let me know if I can help.

 

[toybreaker]

When I get the stancor relay in I'll get it started.... No clue what the cause was. I replaced the GPR in 2015,

 

[Garbage_Mechanic]

You saved yourself about $385 for a new loom from Ford. The good part is there is a lot of good experience in doing this, no trouble will suprise you.

 

[Big Bore]

Nice thread. I'm going to replace my entire harness with a factory one just because I want a known quantity as far as wire condition, and also new UVC harness, gaskets etc. I've had a lot of oil in the engine compartment due to a major HPOP blowout, HPO line blowout and leaking twin pumps. I think my hood liner has a gallon of oil in it now (it's getting replaced also). However, I also really like the idea of upgrading some of those higher current wires as part of the replacement. I like the way the loom covers you made look and I'm wondering if I couldn't slide those right over the factory loom when I do mine, if theres any benefit to that, or should I ditch the plastic loom for this stuff. The plastic has demonstrated it is fragile and prone to breaking.

 

[13fist]

The braided covering I used is a split loom, so it can be installed over the factory harness just fine. That infact was my original plan until I dug into it.
I highly recommend using the Painless performance brand split braid, or the classic. The amazonian cheap stuff it tried to get away with melted where it contacted the engine. Having to redo a finished job is a bummer.

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[Big Bore]

Excellent feedback, thank you. I am definitely focused on having the best possible harness.