starter/solnoid problems
Are you sure that the batteries are all good? The shore power supply is not large enough to supply the current that is needed to turn over the starter for either engine, in all probablility. I don't know just what the genset starter draws, but I know that the one for the chassis is about 100A or more. The fact that neither one will crank seems to me to indicate some problem that is common to both, and not the two different starters.
Are you sure that you do not have battery isolators that are open? The chassis starter draws power from a different battery than does the genset. Have you tried either or both starters when you hold the "emergency start" switch closed? That will connect the chassis battery and the coach battery to supply either starter from both batteries. Also, most motorhomes do not charge the chassis battery from shore powere. There are some Fleetwood motorhomes that do, however. Have you attempted to jump start by connecting to another vehicle with jumper cables? I would do that first and the chassis is probably the easier place to do so. If you have a toad, start in and use jumper cables to connect it to the chassis battery, leaving the toad running. Let it sit and supply the chassis battery for a few minutes before you try to crank it. If it starts, the next step is to charge the chassis battery completely and see if it will hold a charge.
Once you get the chassis engine running, let it run for a while, then try the genset again. If it does not crank use the "ememrgency start" switch to connect the two systems and try it again, with the chassis engine running. That should do the trick.
And come back and keep us updated on the latest!