Ignition switch has two circuits that have to stay connected. One is the full current draw of the ignition system, and the other connects the output of the sidestand/neutral monitor of the starter interlock to the ECU. If that circuit interrupts, the bike dies, just as if the sidestand were put down in gear.. On my Gen-I, if you crank with that circuit interrupted, you get a code 19, but it doesn't set a code just by being disconnected; only when cranking disconnected.
That's not the one that usually goes bad, because it has a VERY low electrical load. Still, it can fail, as it has on my bike. I don't think it's bypassed by the Brodie kit, but I'm not sure.
That second side of the ignition switch will kill the bike without throwing any codes. It only throws a code if it's disconnected while cranking. (And it WILL crank if disconnected, because the switch is behind all the starter interlock stuff, which has already given its OK.) So check it out, There are two connectors from the ignition switch. Disconnect them both. Put an ohmmeter across the one with the little wires. Turn the key on. Should have continuity. Wiggle the key without turning it off. Should not see the continuity flicker any. If you see it drop and come back, you've got a crummy connection in the key switch.
I still haven't worked out in my mind why that line needs to be interrupted by the ignition switch. It's not a safety thing, that's all handled by the sidestand and other interlocks. Maybe the connected ground would set up a current drain in the ECU that can kill the battery.
