Welcome to iRV2.
Sorry your first post is about a problem .
Your issue , sounds like a tripped circuit breaker , or , a bad coach battery disconnect relay . ( the relay controlled by the power switch )
Follow the power cable from the positive post of your coach battery and look for a device similar to the pictures below and check for power in/out of the device .
First two pictures are circuit breakers , third is a disconnect relay .
The circuit breakers should be in the first 3' of cable , if you find a C/B and there is power through it , keep following the cable till you find the disconnect relay. The relay maybe built into a BCC ( Battery Control Center ) fourth picture.