1971 Wiring Nightmare
 

Hello.
The wiring on this truck is completely screwed up. It was running when the engine was pulled, but I can’t figure out how it worked. The truck has an HEI, electric choke, and external regulated alternator. There is no plug for the alternator coming out of the harness...crazy. The black insulated wire is green.
I turned the key on, but have no voltage to any of the wires.
I’m not good with wiring and don’t want to screw this up anymore than it is.
How do you think it goes?
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Re: 1971 Wiring Nightmare
 

If your truck ran before the engine removal, something happened at that time that created your problem.. No disrespect meant but posting a picture of a wad of wires isn't much for us to go on..

This site has an electrical forum. One of the sticky threads in that forum is a posting of downloadable wiring diagrams.. Go there, and download the wiring diagram for your truck.. Trace out and locate the flow of electrons path".. You can then post questions requesting more specific information. As for electric chokes, upgrading to internal regulated alternators, HEI installations, those subjects have been covered in several threads.. Use the site's search feature for that information.. This site is a great place for help with the problems on these old trucks.. You just have to be more specific with "what ails your truck"...

Figured out the alternator. Not sure about the green wire with the rubber jacket.
I didn’t take the wiring apart. I just put the engine and trans back in. All the plugs are gone and have been replaced with spade connectors.
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Re: 1971 Wiring Nightmare
 

I'm a GM certified (retired 1993) electrical technician. The electrical in these old trucks is "right up my alley". I teach like I was taught. I don't spoon feed information.. When you get your hands on that wiring diagram and make some attempts to learn the purpose of that green wire, but can't figure it out, I'll be glad to walk you through learning that..

Green is a color used in engine function monitoring, and among other functions, it's also used in lighting circuits.. The wiring diagram will aid you in determining exactly what your specific wire does... As I previously stated, I can't tell from your single picture, but just looking at your picture, I don't believe the HEI installation/modification was properly done to the wiring..

Re: 1971 Wiring Nightmare
 

If the green wire (Light green) has a woven black tar like sleeve covering it most likely the wire for the temperature switch or sender if you have guages. See photo but ignore the yellow wire coming out of the sleeve as that goes to my electric choke which wasn't installed when the photo was snapped.

Everything is messed up. The yellow to the coil continues with another spade that I think went to the electric choke on the Carter. Those diagrams are tough to see on my little phone.
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Re: 1971 Wiring Nightmare
 

HO455, I would never question your knowledge of these old trucks. I have seen you "in action" when solving a problem for someone. You know your stuff. But it's obvious Perma71 isn't very familiar with the various electrical circuits of them.. He needs to learn this area in particular as the wiring and electrical components are the items most prone to failure.. Spoon feeding information and promoting guess work does nothing toward their "education".. You and I know exactly the function of a green wire protected by a sleeve. Especially if it's in the vicinity of the engine. But according to Perma71, the wiring is "messed up".. Who's to say that wire hasn't been repurposed for another use???.. Our blurting out the answer won't stick with the "student" near as well as when he has to do some of the searching himself...

Re: 1971 Wiring Nightmare
 

You don't have a "full screen computer?? Can your phone be interfaced with a regular sized monitor??? Can you not print off a copy of the diagrams??? Do you have access to the internet besides your phone??? Smart phones have their place in our modern technology.. Viewing schematics, wiring diagrams, and other highly detailed pdf, etc based information isn't one of their uses...

The "yellow to the coil" all the way back to the starter solenoid should have been completely removed as part of the HEI installation.. There are one or two correct ways to supply power to an HEI unit.. There are numerous, numerous ways to do it wrong.. Some will work, most won't..

Off grid on a mountain. We’re working on this property that’s going to be a retreat, so no computer or any nonsense like that.
Thank you for the help. I’ll do the HEI wiring ASAP. The whole harness needs to be replaced though. It’s literally in tatters.
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Re: 1971 Wiring Nightmare
 

I understand.. I'm in a remote area, but not completely "off the grid".. I enjoy the remoteness, but at 76 years of age and poor health, I don't need too much isolation...

Seriously, you'll need wiring diagrams close at hand when you do any electrical work.. With all the years of experience I have, I still often refer to wiring diagrams.. They are an immense aid..

If your under hood wiring is hacked and spliced beyond suitable repair, your best bet is to purchase an exact year specific harness.. You'll still need to make modifications, add circuits, etc to "mate up" with the mechanical modifications already made to your truck.. You'll need those diagrams to aid in that process..

FYI, I bought the truck currently in my avator (sp) about 2 years ago.. It originally was an I6 w/tott.. It now has a 454 w/ automatic.. The under hood wiring was a mess.. Full of wire nuts, unfused runs, and mostly a scary fire inviting mess. I built a new harness accurately reproducing the colors, junctions, connectors, everything as if it came from the factory.. I incorporated the necessary modifications for charging system and HEI.. Works perfectly and cost me less than $50 for the wire, terminals, plugs and connectors... Hang around here long enough and you can probably do the same...