I was sent this article from a helpful support guy at ACS. Helps me understand, but the placard still appears backward to me
. As long as I understand what's happening, then all is good.
After reading...my understanding:
= Both P-Leads grounded...mags won't run if wiring is good.
Switch to R
= Grounds L magneto. R ignition is verified running.
Switch to L
= Grounds R magneto. L ignition is verified running.
As you can tell, my flight training didn't go into great detail on this subject. We of course checked for rpm drop during run-up by switching mags, and checked the OFF position on shutdown before leaning to kill the engine to verify grounds. Building a plane calls out your hand more than only operating systems. Happy to continue learning.