3 minute battery life…?

• Mar 30, 2025

• #1

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Scruffy49

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Tried to crank my truck today. 625a marine battery, fully charged. Truck will turn over, very slowly. Cable end at the battery was branding iron hot…

Truck has sat up for a year. Oil is at the right level. ATF may have leaked out. New distributor and eelated including sparkplugs. Tilt column does have the standadd Squarebody sloppiness.

Battery was flat lined in “MAYBE” 3 minutes. Last time it did this, the starter switch and several fusible links caught fire. Started and alternator have about 6 years on them, but little actual use.

What do I need to check? Rust free 85 C10 swb with a 4.3.

 

• Mar 30, 2025

• #2

75gmck25

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Considering the symptoms, it might be a short to ground. Are you sure you have the polarity right on the battery cables?

 

• Mar 30, 2025

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Sat for a year with the battery connected that whole time?

 

• Mar 30, 2025

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Scruffy49

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75gmck25 said:

Considering the symptoms, it might be a short to ground. Are you sure you have the polarity right on the battery cables?

Click to expand...

Cables are correct.

 

• Mar 30, 2025

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Scruffy49

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CountKrunk said:

Sat for a year with the battery connected that whole time?

Click to expand...

Battery out that whole time. And plastic on the driver side door because the window is stuck down.

 

• Mar 30, 2025

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Scruffy49

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And zero welding done to the truck, with or without battery.

 

• Mar 30, 2025

• #7

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Ricko1966

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Pull the spark plugs and turn it over with a breaker bar. Does it turn easy and free?

 

• Mar 30, 2025

• #8

Grit dog

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Didn’t you just post about the fusible link too?
Are the battery cables from 1985? If so, replace. Also presume new starter spun it over no problem …. Years ago. Did it run then?
Possible causes: starter is drawing too many amps, engine is half seized or way off timing etc causing starter to work too hard, or cable(s) are shot.
Not knowing the condition of the truck and how it was stored for…decades? Or the state of “cranking over” last, whenever that was, I’d start with the above suggestions. Not necessarily in that order.

 

• Mar 30, 2025

• #9

Grit dog

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Sorry, re-read first post. Truck started fine a year ago? Or not?
You did a tune up then or now? On a running engine or not?

 

• Mar 30, 2025

• #10

Turbo4whl

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Marine battery is the wrong battery. May not be the problem, but usually marine batteries do not have a lot of cold cranking amps. Did you check the charge in the battery after sitting a year?

Next thing to check is the voltage drop in both battery cables, one at a time.

 

Last edited: Mar 30, 2025

• Mar 30, 2025

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Scruffy49

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Turbo4whl said:

Marine battery is the wrong battery. May not be the problem, but usually marine batteries do not have a lot of cold cranking amps. Did you charge the battery after sitting a year?

Click to expand...

Battery is always charged for my trailer winch. All of my spare Group 78s are cores.

 

• Mar 30, 2025

• #12

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Scruffy49

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Grit dog said:

Sorry, re-read first post. Truck started fine a year ago? Or not?
You did a tune up then or now? On a running engine or not?

Click to expand...

Started fine in 2023. Ran fine, just way down on power and leaking like the Exxon Valdez.
Tune up was last month. Today was the first time I tried starting it in about 4 months. Been working on the chassis.

 

• Mar 30, 2025

• #13

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Scruffy49

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Has been “off” since my father in law had the coolant changed in 2013. No heat, radiator popped an end tank seam, waterpump siezed. Got the radiator and waterpump swapped, I did the radiator, farm co-op the waterpump. And he then filled it, again, with Dexcool… Truck takes green coolant.
No mouse damaged wires, no possum nests under the hood, new fuel and air filters.
I’ll try it with the Group 78 out of my 99 K3500, but last time, that cost me a battery…

 

• Mar 30, 2025

• #14

Turbo4whl

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@Scruffy49 I edited my first post. Are the battery and cable connections clean and tight?

 

• Mar 30, 2025

• #15

Grit dog

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I’d try the old battery in the newer car first or have it load tested after charging. Much greater possibility the old truck with electrical problems could hurt the newer battery. Or just crank it momentarily. It will either spin over like normal or not. Don’t keep cranking if ist the same.