I have factory manuals that show the routing of the primary wire to the coil, the wire in question is very small and a medium green color. As I recall the secondary wire, coil to distributor is black.
I'll check my trucks, '64-66, and look in the manuals.
The green primary wire would be within the loom coming through the firewall from the ignition switch.
I had a lot of starting trouble with my original '65 in the mid 70's. Heat build up in the main loom restricted the current flow within the wires. High engine compartment heat was the culprit. This was a very common problem in '65 to late '70 C10,20 trks.
I would think that the special resistance wire would be available from one of the aftermarket vendors. I don't think it would work to well to try and splice a new piece of wire to the old wire. Unwrap the loom to find out just were the original wire stops.
I am not to sure just how well the wiring in of a ballast resistor would be, taking in consideration the Start/Run feature built into ignition switches that utilize resistors. Wm.
