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Current deaw.... draining battery

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tweety

tweety

Jedi Trainee
Offline
79 Midget, CA car

All of a sudden, there's something draining my battery. Pretty fast too, 24-48 hours and it's dead.

In the past, I would get a couple of weeks before I noticed any significant loss of juice.

I know I can put in a kill switch, and use a battery tender. I would like to try to find the issue since this is something that went from not too bad to really bad almost overnight.

Any words of wisdom on how to trouble shoot this?
 
The way to find this is pretty much the obvious process: Check the current at the battery to confirm that it's still happening, then check the various branches to see where the current is going. Start with branches that fan out to several loads--that way you can eliminate a large number of possibilities at once. Obviously, you'll need a wiring diagram and an ammeter.

Did this just start happening on its own, or after you did some work on it? If the latter, the recent work is an obvious place to look.
 
This was a huge help for me finding a short in one of my circuits. The only thing I can imagine you needing to do extra is disconnecting all your fuses and checking them one by one - then you can narrow down the circuit.

https://classicbroncos.com/electricalbasics.shtml
 
Good info, JP.

I'd not over-complicate the problem: a 12V test light in series with the ground terminal of the battery, then start pulling fuses one at a time and replacing them 'til the light goes dim or out. Then chase each "device" on that leg of the circuit with the same technique (pull the Lucar connector on each widget and reconnect if the light stays "bright") until the culprit is found.

This kind of draw is usually a light switch in some "hidden" compartment... boot, glovebox, etc.
 
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