1967 wiring harness routing

[papy]

hello,

i knew i would be doubting myself when it came time for the wiring. i have what i believe to be the wiring harness from my 1967, 289 3speed. however i did have lots of parts from other year model broncos as well from the PO so this is only my guess. keep in mind when i bought my bronco everything was in boxes.

can we somehow verify this harness to be sure it is from my 67? i have detailed pics with letters/numbers and i am hoping some of you can help me sort all this out. i amy trying to pre run the wires on the frame rails prior to marrying the body to the frame.

any and all info would be of help. perhaps a diagram of some sort would be great. i have a buddy coming to help me wire everything up when its time for everything to come together.

this is definitely no my cup of tea lol

i will send each sections of the harness separately

thank you in advance.

my current setup is (will be) explorer 5.0, ax15, dana 20

 

[papy]

pic 1

here is a pic of the first section

 

[papy]

pic 2

here is another piece

 

[papy]

pic 3

and another

 

[papy]

pic 4

and another

 

[papy]

pic 5

and the last of it.

 

[DirtDonk]

Hard to tell if it's the exact year, but luckily from '67 to '70 there were few changes.
The last pics make it look like a correct harness with the two rectangular firewall connectors.
The first pics could be, but the harness has been re-worked because the factory used tape and not new-ish looking corrugated split loom.
The relay is not common, and does not look like proper wiring, but I saw a bank of three of those relays on a '72 recently and they even had Ford part numbers on them. No telling what it was for unless someone has experienced them from new before.
It's not a horn relay (or at least not from the factory) since those only appeared on Broncos in '74 and later.

Looks like it's still going to take some sorting, and I would remove some of the old tape to inspect the condition of the wires. If it's dry and the insulation cracks when you bend it, it's time to go with new wiring.
Otherwise you can clean things up, check connections and crimps and fix any damage, and use the old one.

Paul

 

[chuckyb]

If it's not going to be a concourse restoration, you really should consider new wiring for reliability, safety and ease of adding a few accessories. Based on knowing you're doing the Explorer conversion, I think it makes even more sense.

I was also going to attempt to reuse the wiring from my 68, but glad I took the recommendation to get a Centech harness. There are other options out there but for me Centech was the right choice.

 

[jamesroney]

Hi Paul,

The harnesses are unique for each year, although I don’t know what all of the differences are. But from 66-70, with the bulkhead connector on the firewall:

Fuse box location changed in 71.
Marker lights were added in 70.
Windshield wipers added in 69.
Headlight switch moved in 68
Back up lights added in 67.

So...I THINK that you can figure out every harness for every year based on features.

 

[DirtDonk]

Thanks James.
And just to add to what you said about some changes, we've seen quite a few '69's that already had the harnesses for the side markers, even though they had not gotten the lights yet.
The typical running change where some parts got to the Broncos before the rest.
Kind of like the little bumpout for the power steering and the hole for the cold-air intake making it on to lots of later built '72's before the need.

Paul

 

[papy]

Hard to tell if it's the exact year, but luckily from '67 to '70 there were few changes.
The last pics make it look like a correct harness with the two rectangular firewall connectors.
The first pics could be, but the harness has been re-worked because the factory used tape and not new-ish looking corrugated split loom.
The relay is not common, and does not look like proper wiring, but I saw a bank of three of those relays on a '72 recently and they even had Ford part numbers on them. No telling what it was for unless someone has experienced them from new before.
It's not a horn relay (or at least not from the factory) since those only appeared on Broncos in '74 and later.

Looks like it's still going to take some sorting, and I would remove some of the old tape to inspect the condition of the wires. If it's dry and the insulation cracks when you bend it, it's time to go with new wiring.
Otherwise you can clean things up, check connections and crimps and fix any damage, and use the old one.

Paul

If it's not going to be a concourse restoration, you really should consider new wiring for reliability, safety and ease of adding a few accessories. Based on knowing you're doing the Explorer conversion, I think it makes even more sense.

I was also going to attempt to reuse the wiring from my 68, but glad I took the recommendation to get a Centech harness. There are other options out there but for me Centech was the right choice.

I went through the harness and checked for dry wires, cracks and previous repairs and i put some loom on the harness that is ready to be re installed. Surprisingly this harness is in very good shape- i believe its in the shape that is is because the PO who stripped the truck did it back in the mid 90's so it it hasn't really seen 40+ years of use.


i guess i was looking for diagrams routing the harness as to what goes where, what plugs into what and what holes to pass through the fire wall and so forth.

i do have a new painless 28 circuit harness with all the new switches that i was planning on using however if i can reuse what i have then thats what i will do. i got this painless at a good price so i can pass it onto someone else here locally if need be.

question though after Chuck mentioned the explorer swap can i even use this OE harness with my explorer 5.0 set up? i dont see why not but i thought id ask...

thanks

 

[jamesroney]

snip...question though after Chuck mentioned the explorer swap can i even use this OE harness with my explorer 5.0 set up? i dont see why not but i thought id ask...

thanks

I am running the OE harness in my 1970 with the GT40 induction. I don't know what you mean by Explorer 5.0 setup. I think of the Explorer 5.0 set up as the OBD-2 system, with coil packs, and a reprogrammed firewall mounted ECU.

I am running the 93 Mustang 5.0 Cobra setup, and Explorer fuel rails. This uses the the GT40 induction, with the EEC-IV ECU and the 89-93 Mustang harness. This is the RJM harness, that is now the Ron Francis harness.

Regardless, the upper intake is the same, and the problem with the 66-70 factory harness is the bulkhead connector at the firewall. There is not enough room between the firewall and the upper plenum for the pair of 2x4 connectors. I did not have this problem with my 71+ conversions. I mitigated it by moving the firewall plugs and fuse box. It was a lot of work...but since I had the dash out, I figured I might as well do it. I was not about to change my factory harness out for a Centech, since I just spent two days re-wrapping and completely restoring my original harness.

I hope that he attached pictures tell the story...

 

[Steve83]

Look at this & the NEXT several:

(phone app link)

 

[papy]

I am running the OE harness in my 1970 with the GT40 induction. I don't know what you mean by Explorer 5.0 setup. I think of the Explorer 5.0 set up as the OBD-2 system, with coil packs, and a reprogrammed firewall mounted ECU.

I am running the 93 Mustang 5.0 Cobra setup, and Explorer fuel rails. This uses the the GT40 induction, with the EEC-IV ECU and the 89-93 Mustang harness. This is the RJM harness, that is now the Ron Francis harness.

Regardless, the upper intake is the same, and the problem with the 66-70 factory harness is the bulkhead connector at the firewall. There is not enough room between the firewall and the upper plenum for the pair of 2x4 connectors. I did not have this problem with my 71+ conversions. I mitigated it by moving the firewall plugs and fuse box. It was a lot of work...but since I had the dash out, I figured I might as well do it. I was not about to change my factory harness out for a Centech, since I just spent two days re-wrapping and completely restoring my original harness.

I hope that he attached pictures tell the story...

wow i am glad i started this thread. so no way in chance the bulk head connector will clear from firewall to back side of the upper plenum eh?

thank you for posting the pics - makes a lot of sense. i hope i dont have to move the fire wall holes... you thoughts?

 

[papy]

Look at this & the NEXT several:

(phone app link)

exactly what i was looking for! thank you! now i might have some clearance issues with the bulk head connectors and back side of plenum. i dot have the body on frame yet so i have no way of measuring but clearly jamesroney pics prove it. DAMN...

 

[jamesroney]

wow i am glad i started this thread. so no way in chance the bulk head connector will clear from firewall to back side of the upper plenum eh?

thank you for posting the pics - makes a lot of sense. i hope i dont have to move the fire wall holes... you thoughts?

I'm probably not the best person to ask, since my solution took more work than any sane person would do. But the dash was out, and the welder was nearby.
There are surely better solutions than than what I did. But I enjoy working on my Bronco.

Easiest way might be to use a 71 harness, but those are getting hard to find.

 

[Steve83]

so no way in chance the bulk head connector will clear from firewall to back side of the upper plenum eh?

That's a whole different issue - it depends on the engine mounts & their position on the frame, the body mounts & the body position on the frame. There's some adjustment in both of them, so that would change the gap between engine components & the firewall.