I've been living with a hot wire for a while now. (No, not my wife. ;-) ) Fixing it is just a matter of replacing the wire, but I've been putting it off. A few days ago, on the way home from work, I could actually hear it sparking.
It's not the first time it's done that, but this time it was really loud and sustained. I saw the voltage go down at the same time; it must really have been pulling some current out of the other batteries.
The odd thing is... this means there's a path to ground somewhere. Luckily, it didn't short out the 12V system, or even blow any fuses. That means the short is probably among the batteries themselves. I'm betting it's splattered lead and/or dust.
In any case, I'm not moving the car until I replace the wire. With everything else going on, that could take a while.
I really need a vacation.