The voltmeter gauge in my 99 F-250 SD 5.4L was going from 8 volts to 18 volts and the battery light would flash occasionally. I had the battery checked and the alternator by two different parts stores and both said the alternator was bad and both said the battery was good. The battery is the original battery from when I purchased the truck new. Now the gauge seems relatively stable at around 13 volts but the battery light while flash sometimes and the dash lights will flicker. Is it possible that the battery has a short even though it tested okay? Any other possibilities??
Thanks Bill