The joys of wiring....1965 c10 harness blues

[lha1992]

Originally Posted by Lugnutz65

This is from the FSM with my added color. Maybe it is the dark blue and not black. I hope it helps.

Thank you for the help! That's the thing though my truck is an original all gauges cluster truck not warning lights. So why would their be a oil sender wire there at all? The date codes on the truck all point to the time of when the truck was built an everything.

[Lugnutz65]

Let me dig out my FSM and have a look.

[lha1992]

Originally Posted by Lugnutz65

Let me dig out my FSM and have a look.

Thanks brother! I'm quite lost as to what it could be at all. Been looking an trying to figure it out an nothing.

[ray_mcavoy]

That black wire is part of the factory ammeter ("BATT" gauge) wiring. It should go to the large BAT stud on the starter solenoid.

If you look up the wiring diagrams in the FSM, they don't show the optional factory gauge wiring for the 10-30 series trucks. You have to refer to the diagrams for the larger medium/heavy duty trucks instead.

GM put 4 amp inline fuses in the ammeter wiring on the later year 67-72 trucks. I highly recommend adding them to the 64-66 ammeter wiring. They'll save the ammeter and it's wiring from burning up if a poor connection develops on one end of the shunt wire and forces too much current to go through the ammeter itself.

[Lugnutz65]

These pics are from the wiring section of the 1965 FSM supplement. I compared these diagrams to the 1963 FSM and they look the same. All of the V8 wiring diagrams have a black wire (B) going to the middle post on the starter solenoid. Yes, the same post that has the POS+ battery cable. That means the black wire is HOT at all times. The other page shows the black wire (B) terminates on the AMMETER.

I'm trying to help but need to give a disclaimer. I am not an electrical guy so please check this info out with someone else before you fry your instrument panel because I gave bad info.

Here are the pics. from the FSM. The bottom of the page doesn't say C10 but ALL the V8 diagrams show the same wiring for the BLACK (B) wire.

[1963c-10]

Originally Posted by lha1992

Thank you for the help! That's the thing though my truck is an original all gauges cluster truck not warning lights. So why would their be a oil sender wire there at all? The date codes on the truck all point to the time of when the truck was built an everything.

The oil gauges were plumbed in, no wires....the warning lights had wires for the oil warning light.

[kieth]

Wiring you either love it or hate it, I enjoy it, One thing we found as we added the wiring harness from a 91 suburban to my 66 gmc as we rebuilt it, was that GM had not changed the color codes from 66 to 91, all the old color codes still went to the same thing and new devices had new wires with new color codes. Sure made wiring the gauge cluster a lot easier to adapt to the newer wiring harness......Kieth

[lha1992]

Originally Posted by T.J. MCCAULEY

Ah the joys of wiring! Least some people here know how to do this stuff! LOL! When it comes to wiring for me..

Hahaha wiring its fun but can be a challenge an can make you pull your hair out haha. All I say study those wiring diagrams. I work on vintage stereo equipment anyways with restoring those old things so doing this I kinda am use to it but still your working on a bigger scale an you don't wanna mess up something then go boom lol.

Originally Posted by ray_mcavoy

Yes, that's the wire. I forgot to mention that the diagrams use the abbreviation "B/W" for black with white stripe but it looks like you figured that out



The fact that they added a volt meter is probably a good indication that the factory ammeter quit working. It could be as simple as that black wire no longer being connected to the starter solenoid BAT stud. But while you're working on the wiring, it would be a good idea to take a close look at the rest of the ammeter wiring (including the wires under the dash) just to make sure it's all in good condition and still connected as shown on the diagrams Lugnutz65 posted.

Thanks for all the help ray! I am going to go ahead an check the rest of the ammeter wiring to be safe before hooking the gauge backup an sending power through all the wiring. You have a point maybe that's why they added it but idk the truck was setup to pullna trailer cross country apparently cause whoever owned it in the past traveled a lot which I'll post why they mighta added that meter in a bit.

Originally Posted by Dillon Rock

Heck man I should've given ya the wiring harness diagrams from my stash. I also have a new wiring harness sitting under the bench in the garage for the cab. All complete as far as I know. All I did was snag a fuse block clip for my radio spot and that's all I did to it. I'll let ya have it for nothing. No need for it on my part.

Thanks man!!! Its cool about the wiring diagrams I can use them when you get back. But that harness will for sure come in handy I can tell ya that!!! I owe you big time man thanks!!!

Originally Posted by 1963c-10

The oil gauges were plumbed in, no wires....the warning lights had wires for the oil warning light.

Exactly that's what my truck is is the oil gauge was plumbed in an how could it have a oil warning light which then with the help of the guys who posted above helped me find out the black wire was for the ammeter.

Originally Posted by kieth

Wiring you either love it or hate it, I enjoy it, One thing we found as we added the wiring harness from a 91 suburban to my 66 gmc as we rebuilt it, was that GM had not changed the color codes from 66 to 91, all the old color codes still went to the same thing and new devices had new wires with new color codes. Sure made wiring the gauge cluster a lot easier to adapt to the newer wiring harness......Kieth

Thanks for the info kieth!!! I'll deff check out the 73-87 trucks if I need anything extra.