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Old 01-30-2014, 02:09 AM   #1
1968k10blue
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parasitic battery drain

Do you guys know what the amp reading should be in these trucks with everything turned off? I know I have unnatural drainage but need to know what SHOULD be drained normally. My fully charged battery will die in about 10 hours
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Old 01-30-2014, 02:26 AM   #2
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Re: parasitic battery drain

Unless I'm misinformed there would be zero amperage with everything turned off.

The only way to find a short to ground is to start unhooking one thing at a time until you find it and your battery voltage stabilizes
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Old 01-30-2014, 02:28 AM   #3
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Re: parasitic battery drain

That's true, the only thing I can think of that would drain battery 24/7 is my radio, but we will see Friday
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Old 01-30-2014, 04:17 AM   #4
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Re: parasitic battery drain

Lots of things could do it, any place that has a live wire feed.
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Old 01-30-2014, 08:40 AM   #5
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Re: parasitic battery drain

Lots of cars it's the glove box light that will get you, but you don't have that. How's the voltage regulator? They can stick. If you can borrow a clamp style amp gauge then start unplugging things until the draw goes away that is the best way to find a drain like that.
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Old 01-30-2014, 11:17 AM   #6
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Re: parasitic battery drain

Yes, if you can get or borrow a multimeter (DVM) - disconnect the negative battery terminal, put one lead of the DVM on the terminal and put one lead on the cable to complete the circuit, then look at the amps you're drawing. Then start pulling fuses one-by-one until the amp draw stops. That will tell you which part of the electrical system needs attention.
I just had to do this yesterday with my green C20. Turned out to be the radio.

I hope this helps.
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Old 01-30-2014, 12:17 PM   #7
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Re: parasitic battery drain

I uses the full trick and just take the negative battery cable off and bump it against the post, drain=small arc. Pull fuse then bump, when gone the circuit is located.
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Old 01-30-2014, 12:57 PM   #8
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Re: parasitic battery drain

I know haw to I was just wondering what I should try to get it down to, like 50mA or so?
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Old 01-30-2014, 01:41 PM   #9
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Re: parasitic battery drain

have you check the alternator? the diodes could be bad
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Old 01-30-2014, 02:36 PM   #10
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Re: parasitic battery drain

Brand new alternator, slot of the wiring is a hack job right now, but what do you guys think would be an acceptable amount of drain? I know a modern car with all the computers will take about 50mA
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Old 01-30-2014, 03:18 PM   #11
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Re: parasitic battery drain

Jump a 12 volt light between the neg batt pole and the neg bat cable. It will light up. Pull fuses until you find the bad circuit (the light will go out) and then backtrack...
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Old 01-30-2014, 05:37 PM   #12
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Re: parasitic battery drain

Do you still have the external voltage regulator? If so it could be that mine went bad and would drain the battery. I swapped to an internally regulated alternator.
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Old 01-31-2014, 01:28 AM   #13
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Re: parasitic battery drain

The engine is out of a 73 and according to oriellys it was an internally regulated alternator from stock. Maybe but not sure either way it is an internally regulated one
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