I recently set this up as a discrete input on the GAD 27, no resistor or relay, and it works as hoped.
On the G3X, I configured GAD 27 discrete 1, active low, input state: active. This shows an alert when the G3X is first powered on, before engine start. The alert goes away after start, when the alternator is online.
RV-8 Built, sold, missed.
RV-7 Built, sold, missed.
RV-8 Emp in progress ...
RV-8A Purchased, flying.
Last edited by N130WN : 01-03-2021 at 12:40 PM.
Reason: Added detail