Can someone help me . I have been battling alternator issues for some time. Recently bought a alternator from highway stars (ac delco). Car was running 14.4 volts when out in the car. 8 months later I decided to take car out for a drive and it started over charging for up to 19 volts or so the scan tool said. Killed my red top optima battery . Replaced battery and had new alternator rebuilt my a local shop. Scan tool when car is started shows 11 volt to 10.9. Volt light is off . Meter shows 14 on alternator and battery . Please help me understand this. After about 10 to 15 minutes scan tool shows 13.9 which is still low but closer the 10.9