To me, it sounds like the main 40 or 50 amp circuit breaker from the coach battery(ies). Follow the red lead from the coach battery that goes to the BCC. There should be a circuit breaker in that line. It almost looks like a terminal junction, but has two posts. Usually black about 2" square. Between the terminals OR on the side will be a reset button, possibly red or maybe black also depending upon manufacturer.
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