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Battery drain

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athenssprite

athenssprite

Senior Member
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'60 Bugeye drains the battery if I let the car sit overnight. I plan on using the Lucas troubleshooting info. Does anyone have any insight what might be causing this. I still have the positive ground set-up.
 
The simple answer is something is hot that should not be with the switch off.

Get out the tester and check each basic leg till you find it then onward down that leg.
 
Yup... simple things first. Pull each fuse in turn (key out, engine off) and put your multimeter across the terminals. The one that registers current is the one that's draining your battery.

I've currently (ha ha) got a leak on #1, something to do with the new horn, so I pull it if I'm not going to be driving the car for a day or two.
 
I vote for the cutout relay in the regulator box. I'll bet it isn't opening as it should. See any service manual (it's in Haynes, I think) for ways to check this. If that's the problem, you can either readjust the relay (which is tricky) or just get a new regulator. British Parts Northwest (https://www.bpnorthwest.com/) has 'em for $38 right now, which is a notch cheaper than Moss or VB.

Other possibilities are headlights, but I kinda think you can tell if they are on or not (this is not very subtle), or any other electrical stuff you have connected to the unswitched part of the circuit. Some small wire shorting to ground could do it, but this would create serious fireworks and probably (but not necessarily) would blow a fuse.

There really isn't much else it could be.
 
Ummm...yeah, there actually is one other thing it could be, if you can pardon my stating the obvious: could be that the battery has simply died. It's not unusual for a weak battery to seem to take a charge, then go flat when it sits for a relatively short time. I assumed you checked this, but of course I don't really know.
 
Regulator box it is! New one is on the way. It will be nice not to have to disconnect the battery when I park!
 
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