In my '69 Tradewind the original power cord came in through the rear bumper compartment up to the main 30 amp breaker box on the street side wall.
From there the Romex went around the rear to the curb side wall where it split for the univolt and went in the wall and up to the ceiling then forward to the front over head compartment to a sub panel with two breakers one for most of the outlets the other for the outside outlet and bath outlet.
My guess is the second breaker would also power the optional a/c.
I my case I added a 3rd breaker to the sub panel for the a/c I added.
In my reconstruction I brought the power in at midship on the street side to a surge protector then down to a new combo 120v/12v panel . This is where the 30a main breaker is. From there I ran the power to the original wiring going into the wall. I also added an outlet for the new charger.
Back at the new panel I used the other breakers in it to power the refer and microwave,
water heater and the charger .
I brought
12v to the new panel from the battery via a maxi fuse. The
12v is then fused for the water heater DSI, the refer, water pump and TV antenna.
I locate the new panel under the oven compartment. BTW I removed all the original appliances and deleted the oven and furnace. I replaced with a stove top , Refer, water heater, microwave and added TV.
I also added a second 30a inlet with surge protector and separate breaker box for a washer and dryer.
I moved the battery to the curbside along with the
12v fuse panel and updated to blade type fuses and 4 maxi fuses.
I replaced all the copper with pex and moved the inlet to the center street side.
I went with a gel battery and smart charger, no out gassing.