My 2017 Thor class c has a switch on the dash to use if the coach battery is dead you can start the engine from the house batteries. Does anyone know how this should work. My coach battery was dead the other day so I tried the switch, and nothing happened. I know the house batteries were good, they stay charged via a solar panel. Plus the house batteries were able to start my genny.
I went thru the same issue on Tuesday. See the thread Automotive Electrical problems under Maintenance and Repair for all of the suggestions I got.
My problem turned out to be a dead battery, only .5V output. Jumped it from a truck and left the cables hooked up for about 45 minutes. Finally got enough charge on the battery that the Emergency Start switch gave it enough punch to start.