Pertronix---

So----I got my Pertronix kit and studying it I am trying to determine the location to tap the red wire into the ignition side of the ballast resistor. I used my meter to find the ignition switch side of the resistor (2 wires on a plug) but I am unsure where to tap the system. The schematic shows the unregulated power entering the coil of the ignitor (red wire) and the output from the ignitor (black wire) going to the coil. The puzzler for me is the fact that the wire from the low voltage side of the ballast resistor still connects to the coil and I cannot figure out why. Any insight would be appreciated!!!!!!
TIA, Rat