Posted earlier concerning battery discharge and one reply keyed me on a possible BI DIRECTIONAL relay possibility. Does anyone know if there is a bi directional relay in the 2017 Thor ACE 23.9 and if so where it is located?
This link should show you what it looks like. If you toggle the emergency start switch you should here clicking. Follow the clicks. That's the relay that ties the coach/chassis batteries together. The bird controller should be close to that.