ReWiring the Old Trucks

[Doppleganger]

Any you fellas rewired your trucks from scratch? Was wondering how many circuits you found to be enough. I see setups that are 12, 18 and 24. Kind of leaning towards the 18, as 12 doesn't seem to be enough and 24 is almost twice the price as 18.

I get them here: https://www.hotrodwires.com/

100% copper and US made. I never paid any attention til I spoke to these folks - the bigger name brand wiring is all Chi-com and some of it over-rated gauge wire.

My truck has been so bastardized over the years, and 80's stock wiring wasn't known for being high end stuff anyways.....time to gut it and start over me thinks.

TIA

 

[Dmack]

I ordered a speedway universal harness, but once looking at the different circuits, especially when they do switched grounds, I went to a junkyard and found a factory harness in good shape instead.

I did a 20 circuit speedway kit for my 50 F1. The kit worked well, but I pretty much started from zero. 12 would have been fine on that build.

 

[Craig 85]

You may contact @gmachinz He makes OEM style harnesses.

 

[Doppleganger]

Thanks for the input. Was your '50 FI'd or carb'd? I'm adding power everything to mine and got an LS1 waiting to be redone (gonna list a kidney on CL to pay for it if I have to - lol), plus a 4L80e so didn't know how much juice or fuse spots all that needs.

I sent gmachinz a PM awhile ago - maybe on another site? - and IIRC either his inbox was full or he never responded. My mind is soup or I would remember what harness I wanted to ask him about......trans? TBI (at the time)? Dunno.

 

[Dmack]

My F1 is pretty basic. Carbed 289 with a C4. Nothing special but my around town truck.

 

[yevgenievich]

I did quik wire harness on my 67 Camaro. For a square, a stock suburban harness is a good donor with not much modification needed

 

[Matt69olds]

I enjoy electrical work, I’m guessing not many people will say that.

I used a fuse box from a late 80s square body in my 69 Olds. I seriously considered using a Painless Wiring Harness, but with the nitrous, line lock, 2 step rev limiter, etc I would have had to make a bunch of new harnesses and connections, so I made my own. I cut a bunch of connectors, and intact under hood/underdash harnesses from GM cars and my favorite scrapyard. That gave me plenty of the wires with a solid color/tracer. I then ordered a bunch of terminals (series 56 are the most common in these trucks) I then used a sheet of plywood, and started laying out wire. Don’t put the terminals or connector bodies on yet, wait until it’s innthe truck. Leave the wires long, route them neatly and organized. If I had to do it over today, I would not have used harness wrap, I would have used the split loom plastic conduit. Start with the connections from the fuse box the the ignition switch, then one at a time add each circuit and accessory. I spent 3 weeks building my harness, I bet I had it in and out of the car 10 times before I was finished and satisfied.

 

[MikeB]

I installed a universal American Autowire 21-circuit harness in my 82 C10, because I didn't want to spend nearly $700 on their kit made specifically for 81-87 trucks. I spent a lot of time coming up with a way to mount the fuse panel to the firewall. Also, it was a real challenge determining which wires connected to which terminals on the the 20-pin instrument cluster connector. (I used a new connector & terminal kit sold by Ron Francis and several diagrams I found on the internet.)

And then there's the washer/wiper wiring, where you will have to re-use the connectors at the dash switch and at the washer/wiper. Oh, yeah, the turn signal connector mounted to the steering column may require wiring in a different connector than the one that comes with the kit. Be sure to take lots of pictures and make lots of notes before you start tearing out the old wiring!

You will need a crimping tool that works with Delphi/Packard type terminals (like a Tool Aid #18920), a variety of heat shrink tube, and a heat gun to do the job right. And you will need a lot of patience as well as more than a basic understanding of auto electrical systems. FYI, this is the 4th old vehicle I have re-wired, and by far the most difficult.

This is the underdash job with some mods that I made -- 8 gauge feed wire to stud, then 10 gauge wires to fuse panel BAT bus and IGN switch.

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And here's the instrument cluster connector I mentioned:

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[Jrgunn5150]

I'm also ready to rewire my entire truck.

I have weird jumper loops, odd splices, pins falling out of the bulkhead connector... It's all bad.

I've just ordered the Speedway kit, I don't need 22 circuits, but I feel like I need more than 12. The bummer is I'll have to make a bracket to mount it, and plug the stupid hole in the cab, and also salvage a ton of sockets and stuff from the old harness.

But when it's done, it should be sweet. For now, I just jam wires onto the battery to start it lol.

 

[omillan99]

I need to get some stuff re-done also. My harness from the head light switch is burnt up from running my quarter lights once and I learned I did some very questionable repairs about 14 years ago to the some other wiring.

 

[4WDKC]

This is the kit I used for my vette, it clipped to the factory mount that bolted to the firewall but provided nothing to seal the firewall.. I bought a mr gasket shift boot from the parts store, slipped the wires through it, pulled it up over the plastic mount for the fuse panel and poked holes through it so I could bolt it in place.

https://www.ezwiring.com/product-page/ez-wiring-21-standard-wiring-harness

 

[Doppleganger]

I enjoy electrical work, I’m guessing not many people will say that.

I used a fuse box from a late 80s square body in my 69 Olds. I seriously considered using a Painless Wiring Harness, but with the nitrous, line lock, 2 step rev limiter, etc I would have had to make a bunch of new harnesses and connections, so I made my own. I cut a bunch of connectors, and intact under hood/underdash harnesses from GM cars and my favorite scrapyard. That gave me plenty of the wires with a solid color/tracer. I then ordered a bunch of terminals (series 56 are the most common in these trucks) I then used a sheet of plywood, and started laying out wire. Don’t put the terminals or connector bodies on yet, wait until it’s innthe truck. Leave the wires long, route them neatly and organized. If I had to do it over today, I would not have used harness wrap, I would have used the split loom plastic conduit. Start with the connections from the fuse box the the ignition switch, then one at a time add each circuit and accessory. I spent 3 weeks building my harness, I bet I had it in and out of the car 10 times before I was finished and satisfied.

I dont mind it at all - last car I restored I used 5 harnesses to make 1 - which included an updated FI system from a later model. I'd really have to collect alot of harnesses to make one good one in this truck - I've bagged many pairs of pigtails from power windows and such, but everything else on those trucks / vans were shot. The one in my truck is not only shot but has been butchered and spliced - under the hood, in the dash, etc - so many times I dont think any of it could be salvaged. Just want to gut it all and start over with better wire and layout.

I gave up on the Painless and Ron Francis brands when I found they're all Chi-com made now. I've got sub harnesses from some Euro cars (blasphemy I know) for the power windows and locks - they already have Bosch relays inline and are pretty plug and play.

Thanks fellas for all the inputs.