Dead radio, levelling jacks, keypad lock

The things you are having an issue with, in my experience, usually get their power from the chassis battery. This makes the user have the engine running for the levelers (and usually the slides) and the door keypad is allowed to work with coach batteries in off position as would be the case with a salesman's usage or winterizing the rig. In fact, many coaches will have the keypad/keyfob system direct wired to the chassis battery so that with both switches in the off position, the power door locks will work. My Tuscany is set up that way...I can enter the coach via the keypad or keyfob just to check on things or to get something without having to turn on either of the disconnects. With that in mind, I would suspect the issue is with the chassis power, harness and fuses. Beyond that, I can't help much as all my coach experience has been with dp class A units, so, components and their locations, in other types of coaches is better left to those with similar coaches.