wiring harness interchange

[1971ford]

I can't find what i am looking for with the search...

What's the dealio with swapping dash harnesses? mine has too many splices so i'm junking it. It's my '69 f100/f250 highboy with manual trans.
#1: I have to be able to use the 1969 cluster. Reading Keith's right up he says all bezels interchange so i guess i would just have to grab the panel as well off the truck if i get a '70-72 harness. so this still leaves it open to all years.... but the donating truck must not have idiot lights.
#2: I have to use my ignition switch so that limits the wiring harness years from '68-'70. Unless the keys happen to be with the truck I pull a harness from then i can take the ignition housing and put my new lock cylinder in it.
#3 What about accessories? I have cargo light and cigarette lighter. Do all harness come ready for these?

Is this all correct and what am i not thinking about?

I suppose i'll leave the manual/auto trans part out of it since i already have a couple NSS bypass plug deals. I just need that plug and I need to rewire the TSS right?

[bluef250]

I purchased cargo light harness separately. It plugs into harness. The switches on the door that activate the interior lights also have a separate harness. Both were optional equipment.

The ignition switch can be purchased separately and lock set removes from your harness for reuse. The front of the switch wears out. I suggest replacing the front when reworking the wiring. The round terminal style (69 and before) may be difficult to find. The spade style is available. The pig tails are crimped to the trucks harness.

The bezels can be interchanged. They are the same size. In 1970, Ford went to a “printed” circuit and the harness plugs into the bezel. If the printed circuit dies, it is best replaced. Prior to 1970, Ford ran wires to a plug that connected to the harness. The harness plug needs to match the bezel so you may need to connect wires with crimps. Round gauges from a F500 - F600 are a neat addition.

When you rework wiring consider putting in a later model intermittent wiper switch. Very handy upgrade for safety.

What is condition of turning signal self cancelling? You may want to replace the turn signal switch also.

Consider also that the light swtich is more than 40 years old. Replacement may be an option.

The idiot light and gauges have different circuits. The amp/volt gauge is poor so having the idiot light is probably just as good. The oil pressure is important. You may have to replace more than the dash harness if you have the idiot light and use a gauge or vice versa. After market volt and oil pressure gauges might be a good investment.

[1971ford]

The cargo light harness - I have that, from the cargo light to the switch. Is it just that one male plug that plugs into the main harness? I guess that's all it needs so it gets power and the switch lets power through or not.

THe ignition - I bought a new lock cylinder/key set, only issue with grabbing a 1970+ harness is that the key would have to be in the truck at the junkyard so i could pull the old lock cylinder out and put mine in. Mayyybe 1/10 trucks have keys in them. So that would mean i would have to splice my ignition in to a newer harness, and that defeats the point of getting a new used harness because my current ignition plug is loose and doesn't let you start the truck.

I'm not worried about the idiot light think, like you said, the ammeter gauge is pretty much junk anyways and I already have an autometer oil pressure to hang from the dash.

The harness plug needs to match the bezel so you may need to connect wires with crimps.

I'm a little confused.
The bezels 100% interchange from 67-72 right? So doesn't this mean that I can run a 1970+ circuit board panel on my 1969 bezel and not splice anything?

I have bought a intermittent wiper switch, i am adding that in as well as you suggest.
THe self canceling lever has one broken ear, I just don't think i can pull one from the junkyard. Arn't they riveted in?

Thanks for the help. I might take off right now to the junkyard and see what i can find. I am considering simple finding a '68/'69 harness and cutting the ignition switch wiring part off and splicing that into my truck because the main reason for getting a new harness is because my ignition plug is loose and i have to hold it to the ignition to be able to run the truck. The current ignition is already spliced so I'd just re-splice a new plug in and clean up the splices better than the PO did...

[bluef250]

The bezels interchange, they are the same size. The 69 and early use wires with a plug that connects to the harness. The 70 and later harness plug goes directly into the bezel. The 70 is unique, 71 and 72 interchange. If you use a 70 or later you need the proper plug for the bezel.

The ignition plug on the harness side does south. It just falls apart from being hot. I would install a new plug and make the splices.

[fordman]

the 68 /69 harness will hook right up with no problems. the instrument cluster plugs on 70-72 vary. the 70 is one size and the 71/72 is another size. then if you have idiot lights the plugs are also a different size for both years. to use a 70 and up harness witha 68 /69 cluster and some 67 clusters. you remove the plugs from the harness and remove the pins from the wires. put new pins on the wires and use the plug for the cluster you want to use. you could probably do the same thing for the ignition switch too.

[mk]

The bottom line is basically to have the matching cluster to whatever harness you're installing, especially from '70 up. The 67(after nov '66 production)-69 cluster wiring harnesses will interchange directly; there may be at least one wire color change but they still have the same function. Just compare carefully. Installing a newer (70-72) harness into an older truck will require all three engine compartment harnesses as well and is a great upgrade with advantages like a fusible link protected charging circuit. I've just swapped a '71 harness into my '68 and it's turned out well. Only had to swap the turn sig plug and ign switch. The newer harnesses will also work with the '67 heater.



mike