electric steps

Chester
what you are describing is totally sc^^^-up, sounds like feed back from the generator or a relay in the circuit controlled by generator power, none of this should be that way
how many batteries does she have ?
does she have normal 12v power when plugged into shore power ?
steps should be getting power from batteries, with an over ride engaged when the drive engine is on,
could be a crossed wire, the over ride connected to generator run switch instead of the ignition switch, is there a generator start switch on the dash ?

Its possible that the steps are powered by the engine battery and it is the problem. It maybe that the engine battery is charged by the alternator only and not the converter. Try holding down the emergency start toggle switch and see if the chassis battery assist gets the steps to work. (or jumper cable your engine battery if no toggle switch). If so you can take it from there.

I'll take a stab at a possible reason. When the generator is running, it could/should/might supply both 120 and 12 volt power. Since the steps work on 12 volt, power is available. When she is connected to shore power, the coach has 120 volt, but 12 volt would be supplied by an inverter/converter that should/could be charging the house batteries. For some reason, the battery power isn't being supplied to the steps. Aside from run down house batteries, a possible cause could be the solenoid that is sticking and needs replacement. They look like little beer cans with copper arms on each side and small connections near the bottom. They are easy to replace and are available from any auto parts store.

Since the steps work on generator power, a blown fuse is unlikely. While ground wires are a typical cause of problems, since it works on generator power, that's also unlikely.

Good luck.