I have the same problem. I recently had to pull the plug for the air ride compressor, and now, I still have to jump it every week. I think I just need a new battery.. it is old. You might just need to get a new one also..
Your alternator is shot.
Either a short to power or a bad fan switch.
When replacing battery, when servicing some part of the engine, or when the vehicle is not going to be started for over one month.(keeps the radio memory from draining battery)
try disconnecting the battery
I had the same problem on my denaly it is a module in the dash for the heather. even if you turn the key off it is still on
what alarme is it find the wiring digram and remove the fuse
Probably, with that age of car, it's a wrecked battery. The only last 4-5 years, on average.
It means that the alternator is shot or the battery is shot, you need to get the charging system checked out.
my 1992 golf does this... it was due to the new amp and stereo :) fit a spare in the boot solved my problem
Need more info... How old is it? Do you drive short distances? Does it sit around not driven a lot? Check for a short, bad alternator, or fried battery. If you take the car to an alternator shop, they can usually tell you for free if it's the battery or the alternator.
your voltage regulator is stuck ,if it's still factory equip , if not the diode in the alt. is bad.
grab the front bottom edge of the rear seat and pull up, bang there is the battery, i love the fact the battery is under the back seat, this keeps the bat. out of extream temps and helps it last longer.