IIRC, the wire from your old starter going to the ballast resistor is meant to provide the full 12v at start up...for easier starting bla ..bla..bla...once your motor starts that circuit goes away and your coil receives power (a reduced voltage) from the ign switch via the ballast resistor. The easy fix would be to crimp on a lug connector to that wire and connect it up to the same single post on your starter.