1967 M715 Wiring

[Lowcountry]

Ok so here are a few pics of the wiring birds nest I have going on with the M715 I just bought. I’m not sure what the PO has going on here so wanted to get some advice to see if anyone could steer me in the right direction. Is this salvageable or would I need to start fresh and buy a new harness/make my own?

[Lowcountry]

More pics

[Lowcountry]

Alternator

[Lowcountry]

Fuel pump

[Von]

Looks like a 12 volt "conversion".
GM alternator I think? 10si or 12si?
3 solenoids... ?

Since the military connectors to your dimmer switch are intact, and there's a big chunk of the original harness still coming out of the firewall... maybe they left the circuits to the headlights and running lights alone. fingers crossed...

Aftermarket turn signal switch, but they could have tied it into the factory turn signal wiring too.

It's been a while since I've seen a stock distributor... but it looks like... did they cut the top of the dizzy cover and stuff a civvie cap under there?

I'd start with finding out what the loose wires go to.

[Lowcountry]

Ok, thanks I’ll figure out where the loose wires go and post what I find. Yeah what’s up with the 3 solenoids? Yeah I’d say one issue I see I’m going to run into with this vehicle is there aren’t really any detailed write ups compared to the previous vehicles I’ve dealt with; wranglers and early 90s Ford trucks.

This might make it a little more difficult for someone like myself. The guy I bought it from actually ran into the same problem and sold it to me because he said he didn’t know where to start with the wiring and the fact that it needs some welding work done. He said he was starting to go crazy so bought cj to work on like a “normal person” haha.

[Von]

I'm being optimistic and hoping your lighting wiring is still original and intact... because that is the most tedious to rewire. And from the looks of it, you will probably want to rip the rest of the wiring out and start over. Even if it works... it looks like crap. Whether you replace the wiring first or get the truck running and then rewire.
So first goal is to check the light circuits.

My thinking on checking the loose wires is mostly just to see what might be hot and cause a short when you apply power to the system.

If I was doing it... and I am most likely not the best person to be offering guidance...

1: Check that loose stuff. maybe even just tape off the ends to make sure nothing shorts and causes more problems as you're checking the system.

2: Do a physical check of the system for more loose stuff, torn up stuff... check the harness going back and see if it's been molested.
the stock wiring is pretty tough stuff and if it's still wrapped up will be in good shape. When I dissected my old harness, all of it that was still wrapped up looked like brand new. So if the harness is intact I wouldn't mess with it unless you have a problem come up.

3: Apply power to the system and see if the lights work.
The lights on these things are really bad about bad grounds. if some lights don't work check the grounds before assuming the source wire is bad.
bad grounds, rust inside the lights, corroded bulbs.

And I don't know what to tell you on that light switch... I wasn't a fan of the stock 3 way switch. and that one looks like it's been modified.

AND... I've been looking at it from a "rewire it yourself" perspective. Which would be easier if the lighting circuit is intact.

I rewired my truck using a boatload of 12 and 10 gauge wire, cobbling partial schematics off the internet. It took me about 2 weeks to do it and cost about 100 in wire, tools and a couple of fuse blocks, relays...

An aftermarket harness is more expensive but much easier... if you figure in your labor and frustration the aftermarket is probably cheaper...

[venominjected]

American Autowire Highway Series 12 or 15 circuit

$300-350ish... I get it expensive... but comes with new fuse panel, relays, wiring labeled every 6", correct size fuses, and delphi style crimping.

What I plan on doing with mine.. but after my LSx swap into my 1966 C10... I should be able to rewire my m715 with new wiring in probably a day.

[Von]

^ that's a pretty sweet harness.

A guy at work rewired his 56 Chevy with a harness from Painless. He was pretty happy with it.

If you're wanting to go with an aftermarket harness then you could skip everything I wrote above. You'd just need to keep enough of your existing wiring to get the truck to start and run... Ignition, starting circuit and maybe charging system. Oh, and temp and oil pressure sensors. rewire whenever..

You might ID that alternator and make sure what it is. If it is a 12si then I'd keep it. Great alternators and you've already got it mounted...
They aren't as simple to wire as the old GM one wire alternators but they are internally regulated and charge good at low RPMs once they are excited.

I'd also wait on spending any money till I knew I could get it titled. That'd really suck to start putting dough into it and then not be able to tag it.

[Lowcountry]

I'm being optimistic and hoping your lighting wiring is still original and intact... because that is the most tedious to rewire. And from the looks of it, you will probably want to rip the rest of the wiring out and start over. Even if it works... it looks like crap. Whether you replace the wiring first or get the truck running and then rewire.
So first goal is to check the light circuits.

My thinking on checking the loose wires is mostly just to see what might be hot and cause a short when you apply power to the system.

If I was doing it... and I am most likely not the best person to be offering guidance...

1: Check that loose stuff. maybe even just tape off the ends to make sure nothing shorts and causes more problems as you're checking the system.

2: Do a physical check of the system for more loose stuff, torn up stuff... check the harness going back and see if it's been molested.
the stock wiring is pretty tough stuff and if it's still wrapped up will be in good shape. When I dissected my old harness, all of it that was still wrapped up looked like brand new. So if the harness is intact I wouldn't mess with it unless you have a problem come up.

3: Apply power to the system and see if the lights work.
The lights on these things are really bad about bad grounds. if some lights don't work check the grounds before assuming the source wire is bad.
bad grounds, rust inside the lights, corroded bulbs.

And I don't know what to tell you on that light switch... I wasn't a fan of the stock 3 way switch. and that one looks like it's been modified.

AND... I've been looking at it from a "rewire it yourself" perspective. Which would be easier if the lighting circuit is intact.

I rewired my truck using a boatload of 12 and 10 gauge wire, cobbling partial schematics off the internet. It took me about 2 weeks to do it and cost about 100 in wire, tools and a couple of fuse blocks, relays...

An aftermarket harness is more expensive but much easier... if you figure in your labor and frustration the aftermarket is probably cheaper...

Awesome, thanks for typing that out. I really appreciate the help. I should have some time this wknd to work on it so I’ll see what’s going on with the wiring. Yeah you’re right about the title situation, I’ve been thinking the same thing about not wanting to put a bunch of work into it until that gets worked out. The guy said it ran before and over the phone he said I could start it up or at least crank it, but when I got there there it was comletely stripped down as you can see in the pics so I couldn’t do either and I’m thinking hmm not sure if this dude is just blowing smoke so he could sell it or what so I’m honestly not sure of the condition of the motor...people will tell you anything when they are trying to make a sale so who knows if this thing will even run.

If that’s the case I’ll probbaly just have to put a new engine in it which is something I’ve never done so it will be quite a project. I just love the truck so much so I’m willing to put the time and funds in to make it happen. I might even have to bring it somewhere or get some help/guidance from a mechanic, I just know that might end up being over my budget so I’d like to do as much or all of the work myself in order to save money. I’ll be sure to post pics of whatever I do and make a thread because literally if I can end up doing it, anyone can.