The original wiring harness and switch have (at the ignition switch) one terminal that will send power to the coil when cranking only (thru normal wire) to the bulkhead connector, and a second terminal that will power the coil during "run" feeding the resistor wire. Both wires meet at the same terminal on the bulkhead connector and pass thru to the (black pink if I remember right) wire that goes to the coil on the engine side.
Hope this helps.