My 1997 has fuses for the trailer exterior lights (running, brake, reverse) all the way on the back wall under the bathroom sink. This is a terrible location for fuses!!!
If you are the least bit handy, then consider moving the fuses as close to the trailer/truck plug as you can get. In my instance the trailer wiring enters the cabin pretty close to the front, so I can relocate fuses there. Fuses can help if a wire is cut or shorted out or damaged and will blow before a fire happens or worse.
I had a tire blow up and take the trailer floor out and cut all the running light trailer wires. This happened before the fuses, so there was no fuses to blow and stop the electrical current. No fire, but the short melted the trailer wiring on my truck and also did something to my truck's left running light so it does not work.
Move your fuses if you can. Also, consider having fuses on your truck side for the trailer wiring.
Sorry, this does not help finding your camper cabin fuses, but is important.
Fuses should be as close to the power source as possible or practical.
EDIT: My other camper did not have fuses at all. I recommend adding fuses if yours does not, and moving them for sure.