Your charger is probably part of a converter unit that supplies 12v to the coach when plugged into a land 120v line. You may have a panel somewhere inside the coach that accesses the unit. Otherwise, it would be installed in one of the side storage compartments and accessed from the outside. Your manuals should give you a clue. Another suggestion is to follow the leads coming off the battery. They should go directly to the converter/charger, or to a circuit breaker/fuse unit that is located close to the charger. Generally (but not guaranteed), the batteries are close to the charger to keep the cable run short.
2017 Coachmen Orion, Ford Transit 3.7L: previous
'09 Pleasure Way Lexor, '05 NRV Dolphin 5342