No luck at workhorse dealer :) However, on the way back from LA, the state, we stopped at Red Bay AL. 63 acres of Tiffin... 48 bays... very impressive. After tearing apart the connections, the electrical guru of the repair facility found the following: The wiring diagram provided by workhorse showed a wiring change that was never imparted to Tiffin.
There was a connector with port C having a pink wire and port D having a light blue wire. The actual connection had port C with the light blue and port D with the pink, ie reversed. They re-wired the connection to match the wiring diagram. Tested before we left Red Bay, no positify proof that it was the problem, but I am confident. Very impressive also, that once Bob Tiffin was asked to be made aware of the problem, he personally contacted us twice before, and once after we had the repair (and all other warranty work that the dealer had not been able to do, after over 30 days sitting there).
Will post after our next trip with bad weather.