'72 C-10 Electrical Problem

[C10 - C90 Bill]

Jumped into my '72 C-10 today, turned the key and nothing. Not even an idiot light on the dash. Checked the Battery, no. Checked and cleaned the Side Post terminals, no. Checked and cleaned the Neg Ground to the block, no. Looked for any defects in the wires, no. Call a mechanic buddy and he told me that the Cables can corrode from the inside. They are 50 year old originals. Decided to go ahead and change both.

The Negative Cable is about 24 Inches long, but noticed that the Positive Cables come in different size lengths.

I've got a '72 C-10, 307, 3-Speed, no AC and a Side Post Battery. Does anyone know what length the Positive Cable would be?

Here is the listing from LMC:

https://www.lmctruck.com/1967-72-che...junction-block

By the way, I did wiggle a lot of the wires in the meantime. After cleaning up the tools, I decided to give it one more try and it started!! I said, boy am I in trouble now, lol.

[Steeveedee]

Pull the old one off and measure is the only sure way. There is something else loose, or that cable really is toast, and I wouldn't trust it too much longer.

[Sheepdip]

Get some rope, fuel line or similar and route it battery to starter then measure.

[Accelo]

45" for a 350 motor

[C10 - C90 Bill]

Originally Posted by Steeveedee

Pull the old one off and measure is the only sure way.

True, but I'm trying to have it ready to install once I get it out.

[C10 - C90 Bill]

Originally Posted by Accelo

45" for a 350 motor

Thanks

[C10 - C90 Bill]

Originally Posted by Steeveedee

There is something else loose, or that cable really is toast, and I wouldn't trust it too much longer.

Yeah, I'm not even going to trust it till I replace them.

[RustyPile]

Replacement battery cables are as common as belly buttons.. Remove the cables and measure them. Put away the computer and go to your local parts house, chances are they'll have what you need hanging on a rack.. As for the actual problem, There are numerous causes for it.. You have a bad connection somewhere, and the firewall plug and the plug at the ignition switch are the main suspect areas. If you don't already have one, go to the ELECTRICAL forum on this site and download the proper wiring diagram for your truck.

[72SB]

OP

I suspect this 43" would work for your +. IMHO get a #2 size battery cable vs the thin crap at most chain stores

The battery bolt though on this cable is long. I assume for whatever vehicle it is spec for (I just order cables by size & length). You can pop out that long post bolt and put in a short one. They are $1 and in battery section of auto part stores

I got these cables from Amazon. The + one has heat sleeve for running along block. I did bend the eyelet end to starter to "angle" it away

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

This - one should also work
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[HO455]

If this was my truck I would do a check of the fuseable link, by connecting an ohmmeter to each end of the link then wiggle and twist the wire while watching for a loss of continuity. Unhooking one end of the fuseable link will help prevent false readings.
A failing link can cause intermittent problems.

Good luck.

[LockDoc]

-
I would remove and clean the junction block terminal on the passenger inner fender. They can get rusty too.

LockDoc

[C10 - C90 Bill]

Appreciate the additional replies.

[franken]

The big cable from the battery to the starter powers the starter and nothing else.
The OP needs to look at the small + wire that runs to the junction on the fender and beyond, and the small ground from the - side, as well as the ground straps (many of which have probably been lost over the years). from the engine to the cab, cab to frame, etc.