Where did you measure the 120 volts at the panel? Remove the circuit breaker panel cover and check for 120 volts at the feed to the main breaker. Turn the main breaker off then back on. Now check the buss bar voltage or voltage at all the other brekers. Breaker handles must be up to be on. Report back on what you find.
2011 Keystone Sprinter 323BHS
Port Charlotte Fl/Hinsdale Ma
Retired Master Electrician.
I know you believe that you understand what you think I said but I'm sure you realize that what you heard is not what I meant