So, I found out I needed a diode in the exciter circuit because I don't have a dummy light in the truck. Did that, got it charging... but it every time I turned the headlights on it, it stopped charging. My buddy came over, and saw that the belt didn't have enough tension on it.
Sometimes you just need a fresh set of eyes to look at the problem, was so stuck on electrical that I overlooked the mechanical side of it. Problem solved, charges 14.6V all day long. Thanks for your help.