Welcome to iRV2.
First post in two years , boy are you shy .
I take it you haven't found your trailers 12 volt fuse panel , to check the system fuse .
Most vintage trailers the 120 volt circuit breakers and 12 volt fuses are behind a metal ( often brown ) vented panel 8" X 12" at floor level . Vented door has a twist knob to release and fuses will be inside .
I'll see if I can locate a picture.