Alternator wiring harness. 1974

[Bolt]

Does anyone know where I can get a 1974 alternator wiring harness? I see 1973 harness is available but not the 1974.

What is the difference in the two years and since my bronco was built in December of 73 would the 73 work?

 

[DirtDonk]

Not likely, but you could compare them. Most '73's that I'm familiar with started using the "Dura Spark" type connectors on the alternator harness instead of the older flat connectors.
Are yours the later round style? I assume so since the '74's should all have them. Over those years Ford did change a couple of things regularly. One is those connectors, and the other was the strain-relief where it all connects to the alternator.
Maybe they changed the wire orientation at the same time?

The big changes were between '72 and '73, but maybe they were still playing around with things in '74. I just don't know what they are.
Is yours out of the vehicle? Got a pic of it that we can compare to others?

Paul

 

[Steve83]

What's wrong with the original? Just replace each wire with modern XLPE (GXL, TXL, PEX) insulated Copper wire of the same gauge or 2 lower (larger) at most. You can buy the original color combinations on ebay & Amazon in US-made wire for ~$0.20/ft depending on the gauge.

On ebay, search for: (CAR,AUTO,AUTOMOTIVE) WIRE (gauge,numbers,comma,separated,no,spaces) (GAUGE,GAGE,AWG,PRIMARY,TEMP,TEMPERATURE) (TXL,GXL,XLPE,PEX) (color,names,and,abbr.s) STRIPE, but check the description to make sure it's made in USA and the length you need. I wouldn't buy less than 20' of any one wire. You're gonna need more than you expect. I avoid anything smaller (higher) than 18ga, even for low-current signal circuits or small LEDs.

 

[Bolt]

I prescribe to preventative medicine, if I can replace a 46 year old part, I will. Everything else was replaced except the wiring. No issues just wondering why it’s not available. Thanks for the information.

 

[Steve83]

...if I can replace a 46 year old part, I will.

If that's your logic, why not replace the whole truck with a new one? Have you replaced the frame & body tub? The axle assemblies? The glass? If not, they're all 46 years old, too. But like each of them, the wiring doesn't really age - it can be damaged, but if it isn't, there's no real reason to replace it. And even if it IS damaged, it's better to just repair or replace those spots.

 

[Rustytruck]

on my 1974 I needed to replace the alternator harness and I bought a piece of used harness from a used part supplier. On my 1974 Bronco ford used a plug in harness right behind the overflow bottle. you can unplug the alternator section right there and plug in the replacement. it cleaned up the mess I had from the previous owner. I bought some harness wrap and re wrapped the replacement part for an as new look. Plug was the round type as used with Duraspark modules. I bought the part from Randy at driven auto parts.

 

[DirtDonk]

The harness on my '71 is still (or was the last time I looked) in perfect condition. Not like brand new, but almost. On my buddy's '77 however, the wire's outer jacket/sleeve/covering was so brittle you could not even move a piece of harness out of the way to work on something without hearing the snap, crackle and pop of them splitting.
But as said, if yours is still in good shape, it's still working.

Easy enough to test though while things are apart. And wiring is something that should be inspected now and then anyway.
If it's flexible and at least semi-supple, so far so good. Measure for voltage drop between connections and termination points and if none, you're good to go. Maybe for 40 more years.

If not, then it's good you checked, but you might have to roll 'yer own if it's not available. Companies like American Autowire have divisions that only reproduce OE harnesses. Maybe they've got something.
If it's a 1-year only, Bronco only model though, good luck ever finding someone willing to make any. Not without a substantial pre-order, or at anything resembling a normal price. Now, if the same one fits a Ford Mustang as well...

I believe the round plugs with the different pin orientations are the stumbling block still. I have not looked lately to see if anyone is reproducing the various variations, but they've been pretty few and far between for many years. If that's still the case, then taking a new harness for a different year, then simply making your own interface connections using Weatherpacks or some other modern type would be very workable and possibly even better than original.

Good luck.

Paul

 

[Bolt]

Thanks Paul and Rustytruck, I appreciate your input. I recently had a fire in my other vehicle due to the alternator and it’s basically new. That sparked my interest in replacing the wiring in the vehicle that’s most important and just couldn’t get anywhere with the search.

 

[DirtDonk]

As it should! So do tell more please... What vehicle had the meltdown, and do you know what started it?
Just curious in case any of us have the same vehicle.

Ford had it's share of this too, with the so called "2G" alternator before they hit it out of the park with the later 3G models. That 2G was not a bad unit, but their choice of connector/interface wiring was the downfall.

Always curious what goes wrong with modern cars.

Paul