Need a few wiring diagrams and some rewiring ideas.

[Pele]

My truck is a 1989 F350 with 7.3L IDI, non-turbo...

First things first, there's a large connector on the passenger fenderwell that's a melted ball of junk. I assume that's due to the glow plug harness.

A couple of butt splices gets the glow plugs working on the two thickest wires, but I need to figure out where everything else goes so that I can have my oil pressure and coolant temp gauges working again. (Anyone got any ideas on how to replace that connector or should I just bite the bullet and get the engine bay and glow plug harnesses from a parts truck?)


Secondly, the truck frame has been extended, so they cut everything behind the cab. Turn signals, brake lights, and backup lights work okay... But I need to double check the wiring for the fuel level sensors and rear wheel ABS.

 

[MIDNIGHT RIDER]

From what I gather, you just need to wire around that melted connector.

Obviously, the original connector could not handle the load, so another one just like it is not gonna last long either.


Best is to go far enough away from the connector on each side to get into un-burnt wire, clip each individual wire, ONE AT A TIME, and splice/solder/heat-shrink new BIGGER wire WITH NO CONNECTOR.

In the event you ever need it un-connected, simply label and cut each wire at the splice and re-splice when done.


As for the frame wiring, inspect what they did and see if their work is top-notch; if not, then redo their mess.


As for the rear-wheel anti-lock, I have NEVER seen one of those that worked.

Most will freeze up and not allow any fluid whatsoever to get to the rear brakes, forcing the fronts to do all the work, which causes all the cracked rotors, collapsed lines, and poor braking on these trucks.


Myself, I would plumb around that dangerous mess and thus have plain old-timey SAFE no-nonsense brakes.

Like all electronic foolishness, that sort of thing may have kinda worked and looked good in theory way back when everything was pristine; give it a couple years out in the elements and all it is good for is to throw money at and never really work as intended.

I have ran many a RWAL truck (and fully anti-lock for that matter) with the wheels off the ground to find that there was no rear brake activity whatsoever; they would not even drag the shoes nor slow down a coasting wheel.

 

[Pele]

From what I gather, you just need to wire around that melted connector.

Obviously, the original connector could not handle the load, so another one just like it is not gonna last long either.


Best is to go far enough away from the connector on each side to get into un-burnt wire, clip each individual wire, ONE AT A TIME, and splice/solder/heat-shrink new BIGGER wire WITH NO CONNECTOR.

In the event you ever need it un-connected, simply label and cut each wire at the splice and re-splice when done.

Yeah, that's what I was afraid of. Rather than cutting and splicing when I need it disconnected, I'd rather just unplug the individual parts on the engine... But since the whole thing is a melted ball of plastic, I need to figure out what goes where. There are many different colors in there. Hence, I need a diagram.

As for the frame wiring, inspect what they did and see if their work is top-notch; if not, then redo their mess.

Used truck and their work was definitely top notch...

Top notch redneck.

Wires are old Flat-4 Trailer wiring with the White removed... So I have a bunch of browns, a bunch of yellow, and a bunch of greens, all in 4 or 5 strips of Brown, Yellow, Green. Twisted together and wrapped in tape.

I've got the soldering iron and the heat shrink tube... I just need to know what colors go where when I eventually unravel the tape to the factory harness.

As for the rear-wheel anti-lock, I have NEVER seen one of those that worked.

Most will freeze up and not allow any fluid whatsoever to get to the rear brakes, forcing the fronts to do all the work, which causes all the cracked rotors, collapsed lines, and poor braking on these trucks.


Myself, I would plumb around that dangerous mess and thus have plain old-timey SAFE no-nonsense brakes.

Like all electronic foolishness, that sort of thing may have kinda worked and looked good in theory way back when everything was pristine; give it a couple years out in the elements and all it is good for is to throw money at and never really work as intended.

I have ran many a RWAL truck (and fully anti-lock for that matter) with the wheels off the ground to find that there was no rear brake activity whatsoever; they would not even drag the shoes nor slow down a coasting wheel.

Well, fluid passes through. Rear brakes work fine. I have a feeling it's just a bad connection to the rear wheel anti-lock sensor on the differential housing. If it's there, I might as well hook it up.

 

[88beast]

for my rear light ing i used the trailer wire and it worked good also its universal wire where you have something common any idiot knows what it is
if the wire its self is good just redo connections
how many other rear things you need to hook up? reverse lights?
fuel senders? anything else

 

[Pele]

I'm really concentrating on the fuel level sensors and rear ABS sensor... I've got a few wires that aren't connected and all the tail lights work properly, but the fuel gauge doesn't work and the ABS light is on.

 

[franklin2]

I would not permanently splice the wires on the melted plug together. I caught my plug before it melted completely(this is a common problem on the 87-up diesels) so the small wire part of the plug is still good, and I spliced the two fat wires with crimped ring connectors and then little screws and nuts to bolt them together. I appreciated this when I was replacing the valve cover gaskets on that side, I was able to unplug the original plug and unbolt the to two fat wires to give me room to pull the valve cover off.

You are correct, there are many different color smaller wires in that plug. That can be a good thing. If you get a good light and wipe them off, you should be able to match them back up color for color. I would look around for a universal type plug to repair this area. You could even use 6 or 7 prong trailer plug connectors to put the harness back together, but make it easy to unplug to work on the engine.