Congrats on the work-around! Whenever I have an electrical glitch, I always fear the EMS might be dying. Probably not cheap to replace. As you have isolated the problem to one of the circuits in the EMS, if it were me, I'd do a little research to see if this is potentially a "contained" failure or the sign of other problems ahead. If the later, better to deal with it on your time table rather than have a complete failure while on the road. Otherwise, I would say happy RVing!
Good luck some more!