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Old 04-30-2018, 11:43 AM   #1
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Gauge question

I'm going to try to figure this out on my day off (Tues); thought perhaps I could get some input before beginning to check stuff out because I'm really bad at electrical stuff. I do have a tester, and can follow instructions.

1967 c10, factory gauges. Mechanical oil, no tach.
I recently replaced the fuel sender.
My Alternator is new, as is the regulator. Good Optima battery.
Everything working fine until..

I left the truck at the tire shop getting new wheels overnight. It would not start in the morning. Started with a jump. Drove home, shut it off, thinking that they had left the interior light on all night (it sticks). So I thought it would be charged up. But no, it won't start, showed 10.5 volts.

Now, I see that my volt/amp (amp, I think) gauge no longer moves, showing discharge, or charge. (just sits in the middle). My fuel gauge shows 1/4 tank, but I know the tank is nearly full. I did check the fuses on the fenders that go to the volt gauge, they are both good.

This seems like quite a coincidence, so, do you think it's all related?

Going to charge the battery today, and start testing tomorrow. Any tips appreciated.

Last edited by dave`12; 04-30-2018 at 11:50 AM.
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Old 04-30-2018, 12:20 PM   #2
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Re: Gauge question

It sounds like your alternator or regulator has bit the dust. Also it is probably shorted to ground.

Take your battery cables off and charge the battery to full capacity, Optima batteries use a special procedure to charge.

Once it is fully charged connect the positive cable and install a test light or a volt/ohmeter between the negative terminal and the negative cable.

If the light comes on or you have more than 3 milliamps showing on the meter (,003) you have a key off drain.

Watch the light or the meter and disconnect the alternator wires. If the light goes out or the meter shows less than 3 milliamps your alternator is shorted to ground internally.

If the light stays on or the meter stays above the 3 milliamps, disconnect the voltage regulator. If the light goes out or the meter reads less than 3 milliamps the voltage regulator is shorted or the points are stuck and it will have to be replaced.

If the light stays on then you have a drain somewhere else but I think it will be one of those two.

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Old 04-30-2018, 12:29 PM   #3
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Location: miami florida
Posts: 523
Re: Gauge question

thanx vette, I was hoping you would see this.

Would this account for my gauges not working correctly? Sounds like testing just to see batter drain?

Also, I don't have a light on my cheap tester, I've only used it to test volts, though it does have other settings. What setting would show me what you are describing?

One other thing, if the alternator or regulator is bad, I'm thinking I should go to a one wire setup. I'm sure I can find many threads on this, but could you tell me the difficulty rating on this? And the cost?

Thanx again.
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