Did you ever solve this problem? I’m having the exact same issue with my class A right now. Drove it home from storage 3 days ago. Jumped out to get going. Got it home, turned out off for 5 minutes then nothing when turning the ignition. Tried battery boost and generator boost. Replaced battery this morning, still nothing. Nothing happens when engaging the key or when turning ignition full on. Starter was replaced last year. House battery seems to work fine.