overheating 91, 4 litre- complete battery discharge

Hey folks,
I have been diagnosing a overheating 91 cherokee, 4L -6 cyclinder among other things (steering column, compression etc).
I have changed the electric fan switch (initial problem) and remedied that. Works in all cases.
Currently, I am running with the heater full hot in Austin 95 + weather (not fun) and maintaining about 210-200. Which has me thinking the water pump is working because the coolant must be circulating if the temp stabalizes by doing this.
Without doing this, it doesn't take long to reach 240 +. Am working on replacement fan clutch or mechanical replacement.

Okay, today I drove as above (heater on) and then parked it for dinner and 2 hours later the battery was completely dead. Not even lights inside the vehicle. This is the first dead battery issue for this thing. Only thing I can think of is I left the heater fan control switched on when I shut it off.
I am thinking a ground short in this heater circuit? But, would that allow the heater to work at all?
Anyway, any thoughts on this one would be appreciated.

Okay- changed the fan clutch out. Boiled over with the AC on about an half hour later of city driving. Going to try the water pump. Rad looks clean inside.

Intersting note, lost the ability to use the heater in vehicle to blow off heat. Fan worked, air ended up being luke warm only.
Any ideas on the cause of this?

update- heater control valve was fine, new water pump and heater cranks out heat. Radiator was shot. some rails were soldered off closed. Hasn't killed the battery since...very odd

FYI- Just poor battery post connections. No problem since cleaning with wire post cleaner. Duh.