I would dissconnect the pos term, put an ampmeter in series with it, and with everything off, see if there is any current drain. If it's significant, then there is ashort circuit somewhere. Maybey there are some specs as to what the normal drain should be, maybe a dealer can tell you... If the drain is normal, maybe rebuilding the starter may be in order.. Usually brushes, and clean the armature with 600 grit or so...