The small switch may turn off the converter, especially if it is located under the sofa. It will likely hum if the original, so listen for it, then flip the switch. If no hum, mystery solved.
The big switch is likely the disconnect switch for the entire trailer, for long term storage.
Region 3 , 1st VP
Go often to the house of a friend, for weeds choke the unused path........Emerson
Never pick a fight with an old man. If he is too old to fight he will just kill you........a wise old man.