Help with Alternator Install

green wire went to original single field alternator, the other wire went to something else but not the alternator. - maybe a temperature gauge sending unit- or something attached to the coil.

You are showing us a square back alternator that would require 2 field wires. You would have to add a field wire in to have the alternator wire charge and the above pictured electronic voltage regulator. Google Mopar charging system upgrade. its an easy job to wire in.