[The Master Cylinder]

Originally Posted by jerrytocci

The only wireing is the ignition. My question is ....can an ignition switch that is left on kill battery

Originally Posted by Mister Moose

Wouldn't the coil get quite hot if that were the case?

In any event, if you have a mystery battery drain like that and it isn't obvious, I'd recommend taking off the negative battery cable and put an ohmmeter between the disconnected negative cable and ground. It should read infinity, or very high, or open. If you get something less than 1,000 ohms, start looking for frayed wires, accessories left on, something. (That's for a negitive ground system which is original)

If the battery fails and you have over 1,000 ohms, you have a bad battery.

Well first off the OP said the only wiring is the ignition circuit so he shouldn't have to look too far. Second if he does as you suggest and does have a short he will be putting 6 volts directly thru his ohmmeter. Not a good idea.