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1981 to 1985 harness replacement

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Baby Bullhauler

1981 to 1985 harness replacement

Hello everyone, I’m replacing my dash in my 81 f350 that’s been swapped over to a 6.9l from 1985. The original dash and harness was too fried to try and fix so I pulled one from another 85 pickup. I’ve tried using both Chiltons and Hanes manuals but none of the literature covering the cab wiring for either years matches up. I’ve cut each group of wires on both sides of the cab that runs through the firewall to replace with Deutsch connectors for easier repairability. Has anyone attempted something like this, and if so I could greatly use the help as this old girl is my daily driver and I need it running soon as I can manage. Specifically, I need to know what wires need to be paired together on each side of the cab so as to finish connecting the harnesses.

1981 F350 custom, singlecab dually, swapped over to a 1985 6.9 idi and t-19

Gary Lewis

Re: 1981 to 1985 harness replacement

Administrator

Trace - Ford didn't change the wire colors, so you should be able to match up the wires.

But are there specific wires you are asking about? The best reference is the Electrical & Vacuum Troubleshooting Manuals (EVTM) and we have both the 1981 and '85 on the site: Documentation/Electrical/EVTM/and then either the '81 or the '85. They are broken into systems, so if you want to know about the charging system there's a section for that.

Does that help?

Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

Baby Bullhauler

Re: 1981 to 1985 harness replacement

That’s odd because there are a few that don’t match up between what I’m trying to put together. Looking at the manuals, it says certain color wires are in “put spot here” and some are completely different colors. Say it’s supposed to have a black wire with green stripe but it’s red with a blue stripe. I’ll look for the thing you’ve mentioned tho, hopefully that’ll solve my issue

1981 F350 custom, singlecab dually, swapped over to a 1985 6.9 idi and t-19

ArdWrknTrk

Re: 1981 to 1985 harness replacement

Administrator

There's a big difference between a ground leg and a hot in crank wire.

You will find differences between diesel and gas harnesses.
Of course there is no engine ignition harness, but there will be a glowplug harness for the diesel.
Not to mention a second battery, and harness between the two.
A LOT of differences, that make the harnesses quite incompatible (in my experience)

Why don't you swap the whole harness over?

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Baby Bullhauler

Re: 1981 to 1985 harness replacement

Sorry it took a few days to get back. The engine side of the diesel was trashed as it had no core support so cattle got to it and chewed everything up. Engine side on mine was good and Durand park and other gasser related things were pulled before I swapped the new engine in. I’ve got the passenger side mostly figured out, but I’m running into not knowing what needs to go where right next to the fuse panel. Some wires are the same, but the majority are not. For example, there is 24 wires the go through the firewall on the drivers side on both harnesses. I’ve tried to look at the EVTM but I cannot understand it for the life of me. It might also help for y’all to know I’m running the fuel shutoff solenoid off of the wire that used to power the ignition coil.

1981 F350 custom, singlecab dually, swapped over to a 1985 6.9 idi and t-19

ArdWrknTrk

Re: 1981 to 1985 harness replacement

Administrator

The trouble with the EVTM is that it never shows you the whole harness (or even all the circuits in a connector)

It only shows you the one circuit (system) covered by the section you are reading.

You might have charge, start, run and sender wires all in one connector, but you would have to go through the book and find every instance of "C234" and match wire colour to its particular purpose.

Thankfully Ford kept wire colours consistent across brands, models and years for a very long time.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Baby Bullhauler

Re: 1981 to 1985 harness replacement

Right, and what connectors were there are now in place, but there is that group right next to the fuses that has no representation anywhere, unless I’m skipping over it. They go straight through without a connector until on the engine side, and that’s where I’m getting mixed up

1981 F350 custom, singlecab dually, swapped over to a 1985 6.9 idi and t-19

ArdWrknTrk

Re: 1981 to 1985 harness replacement

Administrator

Your '85 dash and cluster are from a diesel truck, a DuraSpark truck or an EEC IV truck?

I don't think that a bulkhead connector is represented in the EVTM, but C121 and C127 cover most of it going through on the left hand side.

Individual wires are best identified by their colour and marking, like you said before.
I mean... any black is a ground but otherwise each colour is distinctive.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Baby Bullhauler

Re: 1981 to 1985 harness replacement

The dash is out of a diesel, sorry if I forgot to clarify that above. And no there is no connector, it’s a group af 24 wires, I’ll look that that image you put in there and see if I can pick anything from it

1981 F350 custom, singlecab dually, swapped over to a 1985 6.9 idi and t-19

Gary Lewis

Re: 1981 to 1985 harness replacement

Administrator

Have you discovered the wiring diagrams here: Documentation/Electrical/Wiring Diagrams?

Gary, AKA "Gary fellow": Profile

Baby Bullhauler

Re: 1981 to 1985 harness replacement

I have, but isn’t that list of people who are best to contact when trying to ring that speck item?

1981 F350 custom, singlecab dually, swapped over to a 1985 6.9 idi and t-19

Gary Lewis

Re: 1981 to 1985 harness replacement

Administrator

Baby Bullhauler wrote

I have, but isn’t that list of people who are best to contact when trying to ring that speck item?

Huh? I don't even know what that means.

But you must have taken a wrong turn. The page at Documentation/Electrical/Wiring Diagrams looks like this:

Gary, AKA "Gary fellow": Profile

Baby Bullhauler

Re: 1981 to 1985 harness replacement

I did take a wrong turn

I found the evtm’s

1981 F350 custom, singlecab dually, swapped over to a 1985 6.9 idi and t-19

ArdWrknTrk

Re: 1981 to 1985 harness replacement

Administrator

http://www.garysgaragemahal.com/wiring-diagrams.html

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.