How exactly did you connect it for switched power and what exactly are you running for an ignition system, AND.....
DO you understand the interaction of the IGN1 "run" and the IGN2 "bypass" ignition circuits?
I am thinking this may be the "key" pun intended.
There are TWO ignition power circuits which originate at the ignition switch, "run" IGN1 and "bypass", IGN2
The "run" wire GOES DEAD during cranking, and in an OEM setup, the IGN2 is hot during start. This IS however, a different circuit (different switch contacts) than the yellow "start" circuit
The bypass/ IGN2 provides power (originally) to the coil + side of the ballast.