Ignition 1 and 2

IGN1 is "run" but it is ONLY hot in "run." That is it goes dead with key in "start." This wire feeds ignition system, alternator field (70/ later) and VR, and electric choke if used, and other smog doo dads on some years/ models

IGN2 (brown) is the resistor bypass circuit and is hot ONLY in start. It is the ONLY source of ignition voltage in "start." If you run an aftermarket ignition system that does not use a ballast resistor, you much jumper IGN1 and IGN2 together