you have the early box reg & only a green wire from reg to alt correct? plug in the green wire female terminal to one of the alt field terminals & ground the other male field terminal & you're set. Amperage comes to the alt internal field via the green wire/enters either field terminal that you are plugged into & come out at the other field terminal that you are to be grounding. Yes the terminal will have some voltage & the reg determines how much or how little depending on the voltage at the blue "sense" wire at the reg on the other side of the "box".