my 1980 cb650 custom keeps melting or blowing the main fuse doesn't happen all the time, the whole charging system has been replaced,i even replaced the wiring on the charging side, only thing i can can figure is the batt won't take a charge passed 12.2 volts when it should be around 12.6..could that be overloaing the wiring causing it to back up and blow the fuse..help..i'm lost..