Hey guys, I'm getting really really really tired of trying to cobble my interior wiring harness back together on my truck. What would be the absolute cheapest alternative to just figuring out what all wires are crossed and or broken? It's a 1970 f100 with a 300, manual transmission, manual brakes and steering, and is a dummy light truck. I know there are drop in replacement harnesses, but i remember them being very expensive and cant afford them at the moment. Thank y'all.

 

I guess it's kind of what you're doing then. Just keep cobbling as you find a fault and fix it. That's what I did to my '71 back when, before harnesses were readily available. But most of those are full vehicle replacements too, which is a good thing when replacing tired old wires. But it's also why they're more expensive.
I know Bronco Graveyard has had some few harness "sections" made over the years, but mostly for Early Broncos and the a few of the most common replacement items for other trucks. Such as under the hood, charging and/or headlight sections. But never seen a full under-dash/interior harness, which would naturally include the fuse panel and a TON of wiring compared to the rest of the truck. At that point, going with a new section is probably almost as pricey as an entire vehicle harness.

Some have purchased new fuse panels with modern ATO style blade fuses, and literally re-wired from there. Panels from companies like BlueSea and Bussman are popular. You can save money, but at that point you're pretty committed to a fair bit of work.
You can even purchase Ford colored wires for not-too-much money if you want.
How is the overall condition of the existing wires? Is it thrashed by age alone? Or was it trashed by a PO that though they were a wiring guru?

Good luck.

Paul

 

I know you stated you weren't wanting a new harness, but I think that is the absolute best way to do it. The wiring in your truck is 47 years old. After time, old wires start to corrode, and the sheathing becomes brittle. There are horror stories of old vehicles burning down because of old wiring. I myself almost had a '69 ford falcon burn down in a gas station parking lot. These problems can be compounded when previous owners cobble wires together. I'm not sure what you consider "very expensive", but American Autowire has a complete harness specifically for 1967-1972 trucks that use factory connections, and upgrades the fuse box to newer blade style fuses. I've seen it as cheap as $720 thru Carolina Classic Trucks. I know this isn't the "absolute cheapest way", but I think it is a very sound investment. Especially if you still want to drive your truck in 50 years. I've attached a link to the Carolina Classic Truck website. The part number for the harness is 510368 just incase you want to look it up elsewhere. Also I believe f100today is an authorized American Autowire dealer, so he might be able to help you out.

 

Sorry, forgot to post the link
https://www.carolinaclassictrucks.co...re-510368.html

 

I got a fuse box out of an 80 something F150, and plan on using it to replace the original fuse box. You should upgrade to at least 14 ga wire, if not 12ga. If you decide to do the wiring yourself, do yourself and the next owner a giant favor. Either use a label gun or buy a electrical number set (Home Depot and Lowes has them) and label the factory wire number onto the wires. Put a label near each end, and at least one in the middle. That way it really doesen't matter what color wire you use, since you can still find the wire number. And the next owner will thank you every time he's under that dash. Use a good crimper and heat shrink along with the connectors. IF POSSIBLE, where ever a wire is attached to a sturdy device, coil the last 2 or 3 inches of the wire ( you can wrap it around a finger or a screwdriver handle- like a little piggy tail). This will take nearly all of the strain off of the connection-and will keep the wire from flexing and breaking off.

 

I used a speedway motors universal harness and re-wired everything when I did it. It wasn't too bad, most of the time was spent making sure each connection was perfect so I didn't have to worry about it later. You will need to use some of the connectors from the original harness for the column, lights, etc...I opted for the 22 circuit but the 12 should accommodate most anything you would need.
https://www.speedwaymotors.com/Speed...ness,2352.html

 

if your where I think you are, it will probably be easier to come see me. I have what appears to be a good complete wiring harness already out of a 72 rigged up like yours.
I bought a parts truck and don't need it. pm me if interested.

 

1970 use one year only printed circuit boards, 1971/72 are different. With Oil/Amp GAUGES or with Oil/Amp WARNING LAMPS is also different.

 

man, I would love to do this. Great price for that re-wire

 

I just looked over that kit. I looks very nice. Good sized fuses and relays too! That is a killer price!