complete wiring harness replacement

[grumpin]

An 88 F250 with the 7.3 diesel I used to own was at one point a wild land firefighting rig. A private contractor.

I wish I had a picture of the unused wiring I removed from that truck. I was able to clean up, repair and use the existing wiring.

At a later point I went through the glow plug system and got it functioning correctly. I’m not certain that the 6.9 and 7.3 glow plug systems are the same.

I would suggest before replacing harnesses, that perhaps you could straighten up what you have.

[Danny Campbell]

An 88 F250 with the 7.3 diesel I used to own was at one point a wild land firefighting rig. A private contractor. I wish I had a picture of the unused wiring I removed from that truck. I was able to clean up, repair and use the existing wiring. At a later point I went through the glow plug system and got it functioning correctly. I’m not certain that the 6.9 and 7.3 glow plug systems are the same. I would suggest before replacing harnesses, that perhaps you could straighten up what you have.

I was surprised that I was able to drive it home. I will attempt to trace and label the wires from the available schematics. 

 

 

It appears to use the same charging and starting components as a gas engine. 

 

On Mon, Mar 1, 2021 at 1:29 PM grumpin [via Bullnose Enthusiasts Forum] <redacted_email_address> wrote:

 

 

 

 

[Dan Crowley]

Hi Danny, I too am restoring an 84 F-250 HD diesel 4X4 that I bought new. I am not sure what condition my wire harness is in due to the fact that I know mice have been in there. So thru my research I've found wire harnesses on e-Bay for about $250 that you don"t know anything about to one's from Painless Wiring which appear to be good quality but cost $1,500 to a company call Ron Frances Wiring, who also offers good quality wiring products for about $600 that I believe will work in our trucks. Check them out on the web and order one of the catalogues, it has a lot of good information and tips on wiring vehicles. Good luck on your restoration.

 

[Danny Campbell]

Hi Danny, I too am restoring an 84 F-250 HD diesel 4X4 that I bought new. I am not sure what condition my wire harness is in due to the fact that I know mice have been in there. So thru my research I've found wire harnesses on e-Bay for about $250 that you don"t know anything about to one's from Painless Wiring which appear to be good quality but cost $1,500 to a company call Ron Frances Wiring, who also offers good quality wiring products for about $600 that I believe will work in our trucks. Check them out on the web and order one of the catalogues, it has a lot of good information and tips on wiring vehicles. Good luck on your restoration.

 

Thanks Dan, I spoke with Ron Francis wiring and they informed me the harness they sale is exact replacement of the original chassis harness, but because the harness is designed for gasoline engines, they are uncertain that their harness could be reconfigured for the idi engine setup.

I’ve used the American Autowire update kit harness (which is a direct fit replacement) on a 78 f150 and is an excellent kit. So, I spoke with AAW and they said the same thing, that it was designed for gas engines only and had not heard of anyone adapting it for the idi Diesel engines.

In my research, I did come across one individual who successfully adapted the AAW update kit to work with his 6.9l idi. I’m currently in the process of removing all of the truck’s wiring intact, except were it has been damaged.

My plan is to purchase the $1500 update kit from AAW and reconfigure the engine setup for the glow plug relay and injection pump cut off. I will document everything and make it available so others will have access to this upgrade.

[Gary Lewis]

Thanks Dan, I spoke with Ron Francis wiring and they informed me the harness they sale is exact replacement of the original chassis harness, but because the harness is designed for gasoline engines, they are uncertain that their harness could be reconfigured for the idi engine setup.

I’ve used the American Autowire update kit harness (which is a direct fit replacement) on a 78 f150 and is an excellent kit. So, I spoke with AAW and they said the same thing, that it was designed for gas engines only and had not heard of anyone adapting it for the idi Diesel engines.

In my research, I did come across one individual who successfully adapted the AAW update kit to work with his 6.9l idi. I’m currently in the process of removing all of the truck’s wiring intact, except were it has been damaged.

My plan is to purchase the $1500 update kit from AAW and reconfigure the engine setup for the glow plug relay and injection pump cut off. I will document everything and make it available so others will have access to this upgrade.

Wow! That's a lot of work, but your research will be invaluable to others. Thanks for sharing - now and in the future.

[85lebaront2]

Wow! That's a lot of work, but your research will be invaluable to others. Thanks for sharing - now and in the future.

The trick would be to take the relevant EVTM and start by going through the front end harness sections and comparing first connector numbers to see if the basic 14401, I believe, harness is essentially the same, I do know that the 1986 gas engine one is common to all from the 4.9L to the 7.5L as the EFI or Feedback carb systems are plug-in pieces.

I learned this when my son had a 1986 F150, 5.0L EFI and I had (and still do) a 1986 F350 7.5L carbureted with hot fuel handling package. fuel pump relay and inertia switch were identical, but the wiring layout to them was different, his being controlled by the EEC and mine by an oil pressure switch. Fuel tank electrical plugs were the same, his harness and mine were very different as his had 3 fuel pumps (2 in-tank and one on the frame) and mine just had 2 very low pressure in-tank pumps with a motor driven 6 port selector, his had the automatic switching valve/filter/reservoir on the frame.

[Gary Lewis]

The trick would be to take the relevant EVTM and start by going through the front end harness sections and comparing first connector numbers to see if the basic 14401, I believe, harness is essentially the same, I do know that the 1986 gas engine one is common to all from the 4.9L to the 7.5L as the EFI or Feedback carb systems are plug-in pieces.

I learned this when my son had a 1986 F150, 5.0L EFI and I had (and still do) a 1986 F350 7.5L carbureted with hot fuel handling package. fuel pump relay and inertia switch were identical, but the wiring layout to them was different, his being controlled by the EEC and mine by an oil pressure switch. Fuel tank electrical plugs were the same, his harness and mine were very different as his had 3 fuel pumps (2 in-tank and one on the frame) and mine just had 2 very low pressure in-tank pumps with a motor driven 6 port selector, his had the automatic switching valve/filter/reservoir on the frame.

True of '86, Bill, but for the previous years there were two different cab harnesses - with and without ammeter. Ford did away with the idiot lights in '86.

[85lebaront2]

True of '86, Bill, but for the previous years there were two different cab harnesses - with and without ammeter. Ford did away with the idiot lights in '86.

Gary, that may be true, but in posting that you confirmed my thoughts, that the cab harness is essentially universal other than the ammeter variable. The Diesel specific items are probably like the difference between EFI, FBC or DS-II/DS-III as each is essentially an "extension" of the cab harness to adapt for the specific powertrain.

[Gary Lewis]

Gary, that may be true, but in posting that you confirmed my thoughts, that the cab harness is essentially universal other than the ammeter variable. The Diesel specific items are probably like the difference between EFI, FBC or DS-II/DS-III as each is essentially an "extension" of the cab harness to adapt for the specific powertrain.

Bill - I'm not sure I can agree as there were a lot of differences, although I don't know what they were:

[ArdWrknTrk]

Bill - I'm not sure I can agree as there were a lot of differences, although I don't know what they were:

It's a whole separate section in my EVTM.

But I don't know all the glow plug wiring and stuff.