Excellent explanation Save! That helps explain why there isn't any current flowing through the blue wire in R. Bedell's wiring diagram (which I'll include in this post, but can't take credit for) with simply the key on.
I knew that the starter button prevented any current from flowing through the heavy red wire to the S/G (if it's working properly) and wondered how the blue wire was energized, if it didin't have any current with the key on, engine running.
This helps me understand why (at 6am).
Thank you!
As soon as the neighbors are up, I'm heading back out there to make sure that it hasn't forgotten how to charge!