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Old 07-22-2019, 02:16 PM   #1
Minkota
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Odd Electrical Drain

I have an electrical drain that will drain a fully charged battery overnight. When I use a meter or test light in series on the ground circuit, I get a 0 reading.
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Old 07-22-2019, 05:44 PM   #2
RustyPile
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Re: Odd Electrical Drain

Either your test is flawed or you have a bad battery?? Charge the battery and leave it disconnected overnight.. IF it holds the charge, then you can re-address your drain.. If it doesn't hold the charge, ---- well you get the idea..
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Old 07-22-2019, 05:46 PM   #3
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Re: Odd Electrical Drain

In the search box...parasitic battery drain....1 possibility pull each fuse. Re check....it's a miserable problem to have to track down....after you do rusties test.
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Old 07-22-2019, 09:58 PM   #4
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Re: Odd Electrical Drain

Are you measuring amps or voltage?
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Old 07-22-2019, 10:06 PM   #5
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Re: Odd Electrical Drain

That, and do you have an inductive ammeter that can be laid on a battery cable to check current? Probably not, that's pretty rare. How are you hooking the test light to a "ground circuit"?

Should be simple. Look for a light on, like brake lights on all the time, even when the pedal isn't pushed down. Stuff like that.
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Old 07-23-2019, 12:34 AM   #6
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Re: Odd Electrical Drain

Maybe a dumb thing, but if pulling fuses, just pull one side of the fuse and do one at a time.
Generally (as others say) you want to measure voltage on a closed circuit (voltmeter in parallel), and current in series and with the ammeter completing the circuit.
Pretty often, the alternator is a source of a current draw.
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Old 07-23-2019, 02:03 AM   #7
RustyPile
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Re: Odd Electrical Drain

All good suggestions. stuck brake light switch, bad dome light switch on the door post. Does the horn work as it should?? If the horn is stuck "ON" and the horns themselves have been disconnected, an energized horn relay will cause a drain.. When you turn off the ignition, be sure the key is in the "OFF" position and not in "ACC" position.

You can use either a multi meter set to read amps or a test light with an incandescent bulb.. LED test light won't work for this test, volts/amps might not be enough to light the diode.. In a pinch a dash light bulb and a couple jumpers will work.. Disconnect either battery cable and connect the meter probes or test light between the cable end and battery post.. Pull one end of the fuses, one at a time.. When the light goes out or the meter reading drops, you've found the circuit that's causing the drain.. In the case of more than one item/component on the circuit, install the fuse and disconnect the items, again, one at a time looking for the light to go out..

Like franken said, I'd suspect the alternator and/or voltage regulator first on the list.. Disconnect the alternator leads including the main charging wire on the big post on the back of the alternator.. In the case of an external voltage regulator, disconnect the 4 leads on it.. Always disconnect one item at a time, looking for the light to go out.. For most people, these tests are simple, but must be conducted in an orderly step by step fashion, or you'll just be chasing your tail all over the place, getting nowhere..

Today's batteries are only good for a couple years and "die" without a warning..As I stated in my first post here, first thing to do is determine if the battery is good or bad..
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Old 07-23-2019, 06:36 AM   #8
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Re: Odd Electrical Drain

some times under hood lites will stay on when the hood is closed rather than when its open, if its mounted improperly. way to tell is to hook it all up as you would normally then go out at nite in the dark and see if there is light shinning from under your hood.
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Old 07-23-2019, 08:06 AM   #9
Minkota
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Re: Odd Electrical Drain

Quote:
Originally Posted by RustyPile View Post
Charge the battery and leave it disconnected overnight.
Sorry, I meant to include that I have already done that and I left the battery disconnected for almost 2 weeks and when i came back it was still fully charged. So I am pretty sure it is not the battery.

Quote:
Originally Posted by vitamin_c95 View Post
Are you measuring amps or voltage?
Amps (Lowest Setting)

Quote:
Originally Posted by Steeveedee View Post
How are you hooking the test light to a "ground circuit"?
Connecting Meter/Test Light in Series between Negative Terminal and Negative Cable.

I am going to purchase a new Meter later this week and retest.

Last edited by Minkota; 07-23-2019 at 08:11 AM.
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Old 07-23-2019, 08:43 AM   #10
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Re: Odd Electrical Drain

Definitely odd. At first when I was checking my for a draw the wrong way on volts. Even then, I was showing 6 volts. Switched to amps, and I had a 1.9 amp draw. You do have the leads in correct spot on meter? That's a pretty gnarly draw for showing zero
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Old 07-23-2019, 12:41 PM   #11
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Re: Odd Electrical Drain

What is the range on the lowest setting? 0 might mean that it has exceeded the range. You should be on a 10 amp range.
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