One other item to note from the schematic.....when the engine is running it operates a lockout relay located in the BCC which disconnects power through fuse F43 that feeds the chassis battery disconnect switch and its lamp at the door. Before the 2014 recall this lockout was used to prevent accidentally turning off the chassis battery while under way. Since the recall directly connects the chassis battery to the ignition the engine will always have battery connection......but other chassis battery items would quit working without the lockout....like your coach steps. The point I want to make is if the engine is running you wont be able to operate the chassis disconnect switch at the door and its light would likely also be out (not sure as my coach is not close at hand at the moment to verify). So the F43 fuse might actually also be OK. F43 is located physically just above the 50 amp mini cct breaker mentioned in previous posts.
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