Gents...thanks for all the replys...
I do have the electric jacks stowed, and slides and steps in. I have started the motorhome before with jacks down and slides out, so I don't believe there are ignition interlocks there.
I have replaced that on frame starter solenoid between the steering column mounted ignition switch and the starter. It is located in the passenger side wheel well. The primary wire was loose on the small post, so I tightened it up, and also cleaned up the two large post wires.
I have not replaced the key switch yet, but that might be my next item. Of course there is still high probability it is a ground somewhere in the ignition circuit. I'm still trying to find a usuable ignition wiring diagram without having to buy a $250 2004 F53 shop manual.