Battery charged but RV won't run on house batteries

confirmed the salesman switch is on and also confirmed all breakers and fuses are on/working at the power center (where converter is under the fridge) - any other breakers/fuses located elsewhere in the rig to check? (yes, we have a voltage meter) And I know a/c, microwave, etc won't run. But right now I got nothing (no lights even) unless I"m plugged into shore.