at first battery volts on dashboard gauge was at 13 volts. then one day it started to drop slowly 11, 12 10. It would click up & down with the same sequence as my signals. brakes , signals , liights would move it up& down. So alternator was changed , battery was charged and now it is overcharging when I step on the gas petal with speed it goes 14,15 volts at idle it stays at 13 volts.