Low Charging Voltage

Hi Folks Car Has Run Great For 4 Years And Volts Gauge Held Steady At 13.5 Volts,
Then About A Month Ago The Volt Gauge Started To Bounce Between 12 And 14 Volts. Then It Stablized At About 12 And Stayed. I Have Replace The Alternator 3 Times And Voltage Reulator Twice.no Help Either Time.
This Is On A 68 Barracuda With The Upgraded Electronics. My Battery Is In The Trunk And When The Car Is Running I Measure 11.7 Volts. The Battery Was Tested Today By My Local Autozone And Proved To Be Good. There Are Times When It Won't Start But If I Put On A New Voltage Regulator It Will Fire Right Up.but Stll 11.7 Volts.about The Only Thing I See Unusual Is When I Try To Start The Car The Volt Gauge Goes To Zero. I Have Gounded Everything Twice. Ballest Resister Maybe?
Any Idea's?
Thanks Terry
Author: admin