Electrical Connections

[leviwatson]

Hey all, I'm working on connecting my engine to the wiring harness and I'm having a hard time doing so. Truck is an 84 k10, but I pulled the 305 that was in it and put in a 350. Don't know the year. Can't find a good diagram to label wires with. Any resources?

I'm familliar with the distributor plugin, but pretty much everything else I'm a little stumped on. Mostly looking to identify the wires coming through the firewall. Thanks so much.

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[Arkansas_V8]

Last picture looks like alternator wiring.

If your heat ain't working, it goes to passenger side of that junction block, dont see it.

 

[1987 GMC Jimmy]

The first, are you looking at the wires coming out of the bulkhead or the ones for the wiper/washer motor? Second, is of the firewall junction block and you also have the TCC lockup vacuum switch in there. Third, I see the ESC bypass connector. Fourth, I see an air injection diverter connector. Last, as mentioned, alternator. There’s probably more than you’re looking for than that. Check out the reference library and the service manual for your year. If there’s an electrical supplement for the ‘84 model, the engine harness diagram will be in there. If not, you’ll have to reference the full manual. The 1984-86 wiring schemes were almost identical, and GM wiring is pretty standardized from 1977-93 so you can learn something from just about any diagram you look at from those timeframes.

 

[leviwatson]

The first, are you looking at the wires coming out of the bulkhead or the ones for the wiper/washer motor? Second, is of the firewall junction block and you also have the TCC lockup vacuum switch in there. Third, I see the ESC bypass connector. Fourth, I see an air injection diverter connector. Last, as mentioned, alternator. There’s probably more than you’re looking for than that. Check out the reference library and the service manual for your year. If there’s an electrical supplement for the ‘84 model, the engine harness diagram will be in there. If not, you’ll have to reference the full manual. The 1984-86 wiring schemes were almost identical, and GM wiring is pretty standardized from 1977-93 so you can learn something from just about any diagram you look at from those timeframes.

Jimmy, I was talking about the wires coming out of the bulkhead. Thanks for all the information! I'll see if I can find a manual. Thanks!

 

[73c20jim]

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If I am not mistaken, that two terminal thing at the top of the picture might be wired wrong. The left side is the power side and the right side is for the accessories. The two terminals are then connected with a fusible link.

 

[Zukeman]

Hello. Im working on the same issue in my 77 K10. Fixing some wiring fixes that happened before I bought itI just can't figure out where the large red wires go too to be sure.
Any change u can shoot me a couple pics of yours ???
Thx, mike

 

[Scott91370]

Hello. Im working on the same issue in my 77 K10. Fixing some wiring fixes that happened before I bought itI just can't figure out where the large red wires go too to be sure.
Any change u can shoot me a couple pics of yours ???
Thx, mike

Go here and choose your truck year and use the wiring diagrams, they'll have all the info you need:

https://www.gmsquarebody.com/threads/1973-1991-wiring-manuals.14498/

 

[Zukeman]

Thank you....