67 Dart electrical problem

The functional path of what I call "ignition run" (IGN1) comes from the ignition switch (dark blue) through the bulkhead resistor, and branches off in the harness to feed the ballast resistor and the voltage regulator. In the original configuration, "ign1" GOES DEAD when you twist the key to start. Direct "battery' coil power is then supplied by a separate contact in the ignition switch, "IGN2". this is hot only in start and goes from the ignition switch (brown) through the bulkhead connector, and to the coil+ side of the ballast.

Might be the ignition switch bad, the bulkhead connector is dirty/ damaged, or another broken wire.

With your ballast bypassed, clip a meter or test lamp on the coil + wire. Turn the key to run, you shouldl have "same as battery" voltage. Twist the key to start, and if the brown is still jumpered to that connection, you should STILL have "same as battery."

If you do, and no spark, you have a tossup------either the coil or something in the Pertronix.

I was not aware you were supposed to operate a Pertronix without a ballast (depending on the coil used) You might want to check that out.