Finally an update on this issue.
We are now in El Paso and as I write this the repair company is here installing a new cooling unit.
Norcold sent a new unit and covered it under the warranty. Our extended warranty company is covering the installation except for our deductible.
This all comes after multitudes of calls to Norcold, finally having gotten to the top of the tech and customer service ladder to get anything done. We had to come to El Paso in December so that service person could be on the phone with the Norcold Tech supervisor, answer tons of questions. After all of that they decided the cooling unit needed replaced.
Hmmm - just what I thought it might have been two months ago.
Hopefully this will be the last time we have to mess with this thing. I do know for sure that if it fails again it's going to the trash heap and a residential unit is going in it's place.
Thanks to all who took the time to answer and send suggestions.