[RipNC]

Another vote for the red 50 amp auto reset breaker. Our 2021 rig came with 80A manual reset breaker on the hydraulics, but the 12v to the battery disconnect switch ran thru the infamous 50A auto reset (now replaced by manual reset). Of that red breaker trips (no indicator other than testing with muotimeter) there is no 12v to the coach. This includes the 12v ignition wire to the inverter! Yes, you'll have 12v there on shorepower (regardless of the auto reset) because the converter is feeding 12v to everything on the coach side of the auto reset breaker.

I'll wager dollar to donut that if you test the ignition wire to the inverter while you are disconnected from shore and w/o 12v in the coach - you won't have 12v there (but you will have 12v at the opposite end of the inverter where the the large gauge wire feeds directly from the inverter battery switch. I've been there and done that, my cause was the inverter was intentionally switch to lithium charge profile and my lithium was taking more than 50A of charge causing the breaker to trip (which also meant batteries weren't getting fully charged. I now have an 80A manual breaker there as well (unless you have lithium 50 will do).