Chevrolet: Caddy Alternator CRAZY!, jumper cables, autopart store

Question
The cadillac section said no expert was available so MAYBE you
can help.
Part 1:  I have a 92 Sedan DeVille V8 that eats car batteries!  I
knew that if I didn't drive it for a couple of days the battery
would weaken.  But after driving it for 45 min on a BRAND NEW
BATTERY it started chugging and trying to die.  As time went on
it began to take less miles to start acting up... now only about 4
miles and it stalls and tries to die (I have to wrestle the gas pedal
to keep it going).  I parked it for 9 months (outta sight-outta
mind!)

PART 2: .  Tried to charge the battery- would NOT charge.  Tried
to jump start battery- FINALLY got it to start but... after
disconnecting jumper cables ANYTHING would kill it: opening
the door, stepping on the brake, ect...
Then I noticed (right after jumping it) that someting under the
dash was SMOKING HOT!  I think it't the brake release or the
gearshift release on the steering column. Direct Short? Parked it
for 3 more months.

PART 3:  ASSUMING I had a short, I installed a new battery.  I
watched my V.O.M. dropping voltage from across the battery
terminals (without engine running).  I disconnected the hot wire
from the alternator... voltage still dropping.  I disconnected the
smaller wire plugged into the back of the alternator and it
stopped dropping!  (What is that little wire?)  Then I detected a
short from the alternator hot terminal to the caseing.  Not a
dead short but some leakage.  The nice man at the autopart
store checked the alternator on his machine and said, "yes. it
needs to be replaced but another short in the car probably
caused it to go bad".  

Now I'm afraid to buy a $150 alternator in case I burn it up.  But
my gut tells me IT is the problem.
HELP! What does this sound like to you?

Answer
Hi Randal, if there was a short it would cause the alternator after a while, if you think you have the short fixed it will be fine. Now for the wires, the red one that screws to the back of the alternator supposed to be hot at all times, the plug on the side (some have one wire and some have two) if its two wires the big one supposed to be hot at all times, the small one is supposed to be hot with the key in the run position, this is to energize the alternator, so with the key off there should be no power on the small wire.I hope this helps you if you need more info just let me know. Regards, Keith.