55.2-59 Battery draining

[leegreen]

It sounds like you already fixed the large battery goes dead overnight problem.

When the MM gets confusing, you could put your new test light between battery and negative then disconnect stuff one change at a time until the light goes out.
Leave that last thing disconnected, it is one of the problems, maybe the only problem.
Next double check to see if there is a second problem: reconnect everything else to see if one of them makes the light come back on

[dsraven]

great advice LG.
theoretically, the mm between the battery post and the battery cable should read zero volts or amps with the key off unless there is a connection somewhere in the system to complete the circuit. a test like LG advised to do with the test light would help find the culprit with less leg work so you wouldn't have to pull a fuse and then get up to see the MM. this works as long as the "draw" has enough of a connection to light the tester bulb and you can also see the tester from the work area. I have used a buzzer for the same thing but it is annoying.
I think I asked before, but do you have a gauge package connected? is it possibly getting power with the key off?

[mr48chev]

That theory will hold true provided there is nothing in the system that draws constant power.

Things that draw legit constant power:
memory in some radios and clocks. If every time you disconnect the battery your radio loses it's channels it is drawing a few miliamps.
Alarm systems. When you turn them on they are drawing similar low amperage as the memory of the radio.

[franken]

Regarding the stop the nonsense statement there's been no shortage of fictional electrical theory spouted in this thread so why call out someone trying to make a distinction that's valid? Current and voltage aren't the same. Measuring them is also different.
Voltage is measured across a load (no interrupting the circuit), current is measured by putting an ammeter in series with the circuit (interrupting the circuit).
The OP should read a bit about Ohm's Law (it's simple) in order to understand WTF is going on and which theories are BS. In this case E is 12V there are only 2 remaining variables.
BTW, Ohm's Law was valid when each of us went to school and it is today.
Had more people understood the law and made sensible posts or none, this issue would have been resolved sooner...
Understanding a tiny bit of electrical theory goes a long way to helping people to understand when thay's on the wrong track.