Open plugs/connectors

[JackJ217]

I’m wondering if anybody knows what these open/capped plugs are for? This is the drivers side right under the brake booster and cruise control vac canister.
87 f250 6.9 4x4 originally an auto c6, in the process of swapping in a zf5.

First plug has a cap on it. Wire colors are Red, yellow, black, brown
Second plug also has a cap. One red wire, one green wire.
Third plug is open with just a green wire going to it.
Fourth plug is open with a red/lt blue wire and a green wire.
There was also 3 cut wires tied together with electrical tape coming out of the main harness that goes through the firewall. Red/yellow, red/white, and black/blue or green - can’t tell which one

Is one of these for the manual trans harness that I can tie into for the neutral safety switch and the reverse switch?

 

[franklin2]

You should have a plug in the same area that feeds a harness that goes down the frame to the c6 and the transfer case. This is the harness that has the neutral safety. I had a donor truck when I did my zf swap, all I had to do was to unplug this tranny/transfer case harness, and plug in the tranny/transfer case harness from the donor, no wiring to do at all.

If you do not have the zf harness, you need to get into this wiring harness to the c6 and find the red/blue wires, there should be two. Cut these two wires on the tranny side and twist them together, this will complete the starter circuit and let it crank over, since you will no longer have a neutral safety switch with the zf.

 

[JackJ217]

You should have a plug in the same area that feeds a harness that goes down the frame to the c6 and the transfer case. This is the harness that has the neutral safety. I had a donor truck when I did my zf swap, all I had to do was to unplug this tranny/transfer case harness, and plug in the tranny/transfer case harness from the donor, no wiring to do at all.

If you do not have the zf harness, you need to get into this wiring harness to the c6 and find the red/blue wires, there should be two. Cut these two wires on the tranny side and twist them together, this will complete the starter circuit and let it crank over, since you will no longer have a neutral safety switch with the zf.

Thanks. That’s the main thing I’ve been trying to figure out. I did have a donor truck but somebody had robbed the harness out of it before I got it

 

[franklin2]

On the other open plugs, they had a trailer lamps relay option that you probably do not have, and they also had a marker light relay option that the dually pickups came with. The brown wire is the marker light circuit.

 

[franklin2]

This diagram shows the cut wires on the left side. They were for a trailer brake control.

You must be registered for see images attach

 

[XOLATEM]

Having a wiring diagram is one of the most helpful things that a man can ask for. Puts you right on track for answers.

I always appreciate @franklin2 's input. One of the sharpest, no nonsense mechanics I have ever come across. 'Nuff said.

I learn something every time I read what he has to say.

There, I said it.

.02


Postscript...

After thinking about it for a few minutes I want to thank all of you guys and gal for teaching me pretty much all I know about the diesel engine in my truck and how to keep it running by deciphering the mystery of its principles of operation.

Thank you all...!!!

.02

 

[JackJ217]

Having a wiring diagram is one of the most helpful things that a man can ask for. Puts you right on track for answers.

I always appreciate @franklin2 's input. One of the sharpest, no nonsense mechanics I have ever come across. 'Nuff said.

I learn something every time I read what he has to say.

There, I said it.

.02


Postscript...

After thinking about it for a few minutes I want to thank all of you guys and gal for teaching me pretty much all I know about the diesel engine in my truck and how to keep it running by deciphering the mystery of its principles of operation.

Thank you all...!!!

.02

Is there a place online with the full wiring diagram? I would love to have one but I don’t want to spend near $100 for one on ebay lol

 

[XOLATEM]

Is there a place online with the full wiring diagram? I would love to have one but I don’t want to spend near $100 for one on ebay lol

I hear ya, but sometimes spending money can't be helped if you gotta get something running or otherwise figured out in a hurry.

So far, I have been able to find what I needed here...but I have thought about going on Rockauto and getting the tech discs they sell.

1987 FORD F-350 6.9L 420cid V8 DIESEL Repair Manual | Shop Now at RockAuto

Literature Parts and More for Your 1987 FORD F-350 at Reliably Low Prices. Fast Online Catalog. DIY-Easy. Your Choice of Quality. Full Manufacturer Warranty.

www.rockauto.com

Look into that and see if it suits ya...

Good luck and happy trucking,

.02

 

[onetonjohn]

This is pretty awesome. And Free. It's for Bullnose, but may not have changed a ton.

1986 EVTM

Many thanks to Bill Vose for this copy of the 1986 EVTM. It is broken into the following sections: Introduction & General Information : (Index through Page 4) Includes the index, how to use...

www.garysgaragemahal.com

If I could find a good paper copy, I might buy on in case the internet goes away. Copyright must be up on this. I think they are 25 years. One of the benefits to having an old truck I suppose.

 

[nelstomlinson]

If you can find an EVTM on fleabay, they're unbeatable.

 

[Kdo58]

The best money I spent

11 x 17 COLOR Wiring Diagram for Ford F100, F150, F250 F350 1987 Pickup Truck | eBay

Make & Model: Ford F Series, F100, F150, F250, F350. YOU WILL GET A DIAGRAM - NO MATTER WHAT. Prospero's Wiring Diagrams presents 11 x 17 - Bigger than other wiring diagrams. The Quick and Dirty on Our Wiring Diagrams.

ebay.us

You must be registered for see images attach

 

[onetonjohn]

Look nice. Do they have diesel specific wiring, or is it only gas engines?

 

[Kdo58]

It covers them all

 

[JackJ217]

The best money I spent

11 x 17 COLOR Wiring Diagram for Ford F100, F150, F250 F350 1987 Pickup Truck | eBay

Make & Model: Ford F Series, F100, F150, F250, F350. YOU WILL GET A DIAGRAM - NO MATTER WHAT. Prospero's Wiring Diagrams presents 11 x 17 - Bigger than other wiring diagrams. The Quick and Dirty on Our Wiring Diagrams.

ebay.us

You must be registered for see images attach

That’s exactly what I need. Thanks. Just ordered one

 

[JackJ217]

@franklin2 in the harness that goes to the trans, I’m seeing that the black/pink and pink/orange are both for the reverse lights. Is one power and one ground? I was able to get the pigtail for the reverse switch for the zf5 from the guy I bought the shifter arm from, so not sure what year the truck was. It has a black/white (or pink?) wire, and the second wire I have no clue. It goes from blue/white to purple/orange and then back to blue/white lol