> Thanks to the member (Jim?  Bill?) who suggested using a G.F.I. outlet >($7.99 for contractor grade) instead of trying to find a suitable >circuit breaker replacement

A G.F.I. outlet is NOT the same as a circuit breaker.  A circuit breaker limits the total current flowing through the circuit so you don't burn up the wiring.  A G.F.I. limits the amount of current flowing through stray paths to ground (like if you touch the hot side of the line while touching the body of the van) but does nothing to protect the wiring from fire.  You need the circuit breaker if the van is ever plugged into any circuit with a breaker larger than 15A (like when you use an adapter to plug into a 30A RV panel) and you need the GFI if you ever operate an appliance under wet conditions (like near a sink).

Bill