Although an RV power converter box could be placed in a variety of places on board, it is usually close to the 110 volt AC breaker box and the 12 volt DC breaker box.
The 110 volt AC line leading to the RV power converter may originate from the 110 volt AC breaker box or directly from the incoming 110 AC volt pigtail.
There is also the possibility of the RV power converter being part of the 12 volt breaker box itself. If so, it would likely be behind the 12 volt DC breaker panel.
In some cases, this breaker box is flush mounted on the side of the bed in the master bedroom. Access to the converter box may be achieved by lifting the mattress from the frame.
Most of the power converters installed in the latest RV's and camper trailers will likely have the combination converter/breaker box unit. Your particular RV may be different or possibly changed in the past.
The wires connecting the main 12 volt DC panel should lead directly to the converter, wherever it is located.