Check your circuit breakers as Drew said. Is it just the inside switches that won't work? Or is the switch on the genset not working also? Do you have 12 v at the starter? Sometimes voltage may be present but enough amps are not getting through to the starter. Battery terminals may look clean on the outside but corroded or lose on the inside check to see if the positive cable going back to your genset is tight inside the terminal(wiggle it back and forth). There are other things to check but check these thing first and let us know what you find.
