i think i answered this one before but you need to do an amps drain test on the battery.easy to do with a multimeter.remove earth lead from battery and put multimeter in line on amps setting.it will tell you how manny amps are draining.i imagine it will be high.then remove one fuse at a time until it stops,you have now found the curcuit thats at fault.it is a short in that curcuit.a live that is earthing out.
mikec
May 2009