Resolved Engine Ground
I contacted Spartan and according to them that if the jumper went from the battery negative and enabled it to start, that the ECU, neutral safety, water in fuel, etc. were all bypassed.
We did have someone familiar with the RV come down and look at it and he resolved it, mysteriously in minutes. We had someone clean the corossion off the cable ends, chassis mnt. and starter. But the person who found the issue had said that a cable was left off the starter. That would have been the case since before the batteries were replaced and no one even touched the wiring.
It seemed like it was something else.
Anyway, all is back running including the genset and another issue where someone, a while back, had bypassed a power lug in the BCC to provide interior power.
Thank you all for contributing!!