Cab wire harness part #?

[Ford F834]

I meant to boot up the computer last nigh and look for this in the MPC but I spaced it.

I’m heading to the pick a part on my lunch hour and was hoping to pull one, maybe two cab wire harnesses. I’m wondering how many different ones there were, and what compatibly there may be across years and engines.

I want the IDI harness if it’s any good as I suspect it may be unique? And might prove useful for a diesel swap or Bullnose dash swap?

I think I would be time and $ ahead to get a whole new harness for the ‘81. I have tried and cannot seem to sort out the issues with my headlights cutting out. The tail light circuit has never been right, and there is generally a lot of butchery that I would like to correct. I’m hoping some other DSII cab donors might work if there are no good condition I-6?

[Gary Lewis]

I'm looking in the MPC but not finding it very quickly.  But, I'll take a stab:

There was one for each different engine family as the location of the oil pressure and water temp senders varied by family

Then there were variations for engines with and w/o the various relays, like TAB and TAD.

Luckily the EEC harnesses were add-on, I think, until you get to the TFI systems.  And come to think of it there maybe just differences in the ignition harness for them.

[Ford F834]

Thank you Gary, what are TAB and TAD? I was hoping the cab harness might have been modular and independent of the engine type, but you are thinking that cab and engine bay harness were mated and particular to the engine family? In that case I hope the IDI harness is good, and I hope I can find a good condition 300 six cab...

[Gary Lewis]

I think the cab harness is the same across most, if not all, of the engines.  The exception might be the IDI, but the glow plug controls are probably an add-on circuit.

It is the engine harnesses that changed by family.

So maybe I misunderstood?

TAB and TAD are emissions relays/valves.  Think they are air diverter valves for the AIR system.

[Ford F834]

Thank you! That’s more what I was hoping for... that the main cab harness might be interchangeable with different plug-ins. As we have discovered, some of the connectors changed through the years (e.g. HVAC switch, clock etc.) but I am hoping that I might be able to take just the cab harness out of a V8 truck since they are vastly more common and l am more likely to find one in good shape.

[Gary Lewis]

Yes, I think you can.

[myrl883]

14401 harness doesn't connect to the engine. If you look at the catalog, the harnesses are different depending on gas or diesel, single or dual tanks, w/ or w/o ammeter. I'd just look for a truck the closest to what you want yours to be, and modify from there.

[FuzzFace2]

myrl883 wrote

14401 harness doesn't connect to the engine. If you look at the catalog, the harnesses are different depending on gas or diesel, single or dual tanks, w/ or w/o ammeter. I'd just look for a truck the closest to what you want yours to be, and modify from there.

I can tell you what I have found when I swapped the harness between my 2 - 1981's both with 300 six.
The cab harness (across the dash) also goes out into the engine bay on both sides of the firewall.
The left side plugs into the rear frame rail harness, DSII, washer pump, and the lights / horn on that front corner.
The right side plugs into blower motor, plug for the charging system, and the lights on that front corner.

I can tell you if the truck has duel tanks this is a different cab & rear frame rail harness.

Add on harness: AC is a plug in by unplugging the blower wire? loop.
Radio speaker wire harness. Clock may have a short extension harness.
That is what I remember when doing my "rewire" job.

In a few weeks I hope to pull apart 2 trucks (83 & maybe 84) to make 1 good one.
The good one started as a 302 feed back system that has be butchered, Truck shows AC & speed control (on wheel but nothing else?) and power door lock switches but don't know if this is true? This full harness will be pulled and the next installed.

This truck roof rotted off, has a 300 six, AC & speed control both under hood and inside. No cut wires that we can see and why we plan to use this harness in the other truck and extend the needed wires to work with a 302.
Because I did the harness swap in my truck I said I would do this swap (with help) on his trucks.
I can report back what all I find if that will help.
Dave ----

[Gary Lewis]

Myrl - Thanks!  I created a page to capture the wiring harnesses: Documentation/Electrical/Wiring Harnesses/Wiring Harnesses, but to this point only have the cab (instrument panel to dash panel) harness included as I had no idea that there are as many different harnii as there are.

But if I've missed some please let me know.

And WOW!  I had no idea there were that many different cab (instrument panel to dash panel) harnesses for the F-Series trucks:

1980: 4  With & without gauges and with & without aux tank
1981: 4  With & without gauges and with & without aux tank
1982: 4  With & without gauges and with & without aux tank
1983: 6  With & without gauges and with & without aux tank, diesel, and 460 hot fuel handling
1984: 6  With & without gauges and with & without aux tank, diesel, and 460 hot fuel handling
1985: 18  I can't get my head around all of the changes
1986: 8

[FuzzFace2]

Gary Lewis wrote

Myrl - Thanks!  I created a page to capture the wiring harnesses: Documentation/Electrical/Wiring Harnesses/Wiring Harnesses, but to this point only have the cab (instrument panel to dash panel) harness included as I had no idea that there are as many different harnii as there are.

But if I've missed some please let me know.

And WOW!  I had no idea there were that many different cab (instrument panel to dash panel) harnesses for the F-Series trucks:

1980: 4  With & without gauges and with & without aux tank
1981: 4  With & without gauges and with & without aux tank
1982: 4  With & without gauges and with & without aux tank
1983: 6  With & without gauges and with & without aux tank, diesel, and 460 hot fuel handling
1984: 6  With & without gauges and with & without aux tank, diesel, and 460 hot fuel handling
1985: 18  I can't get my head around all of the changes
1986: 8

WOW
We know the 80 had different wire pin out but I wonder if you could use 81/84 (less the diesel's & hot fuel handling) for a swap or upgrade (aux tank or gauges)?

For 83/84 the diesel & HFH did the trucks come with gauges only?
Other wise you would have 8 different harnesses for them years if I count right.

I guess I was lucky I had an almost match for my harness swap in the 81.
Both had gauges and 1 with & 1 without aux tank, I used the aux tank harness.
Dave ----

[Gary Lewis]

Yes, I think the diesels and 460's must have come with gauges, although I've not seen that in other documentation.

[85lebaront2]

Probably the reason for 18 in 1985 was the mid year introduction of the EFI 5.0L, that is at least 4 if not more right there single vs dual tanks, then if you add w and w/o gauges to those 4 it makes 8 there alone. Since the AC systems were a piggyback harness that plugs into the basic heater only harness it will be a separate PN.

This is most likely why the change in 1987 to separate dash and front harnesses. From what I remember my 1977 had molded rubber plugs at the firewall for lights & horn and then one for the engine including the DS-II system. I have never understood why Ford went to the single combined harness in 1980.

[Ford F834]

WOW!!! Thank you Gary, this is awesome! I was unable to go to the yard yesterday, but today it’s a plan. If I am successful at pulling two harnii I will try to see what the main difference might be between gas and diesel.

I can say that I have never seen a diesel with idiot lights. I have never seen a single tank diesel either. I can also say that 83/84 diesels lacked the tachometer circuit option. I’m guessing early 85 lacked it also given the note “From 2/85” on one of the diesel ones.

***Thank You for all of the work you put into this!***

[Gary Lewis]

1985 was a confusing year.  But compare it to '86.  There were many changes.  And, they dropped the idiot lights in '86 and made the gauges standard, which really made things a lot more simple.

Jonathan - You are welcome.  I realized that all the harnii appear to have "Wiring Assy" in the title, which gave me a way to find them.  But I had no idea there were so many kinds of harnii, nor so many within each kind.