What are the possible culprits of drawing the power out of the main battery
on an '81 westy?  I have an isolator installed and my charging system is
great.  Both batteries are full every time I shut my van off, however, after
a few days the main battery will be dead.  I've disconnected the clock and
I'm going to see if that makes a difference.  If that's not it and it's not
just the battery itself, what other possibilities are there?  Your insights
are much appreciated.

Thanks,
Danny
'81 Westy