The dealer fix did not last more than 2 days. By the time we got to Oklahoma, the weather was so mild that we needed neither heat or A/C in the cab. Likewise, on the way home, weather was so nice it was not a problem. Dropped off the coach today with a list to fix and the cab heat and A/C is at the top. I'll post again when resolved. I think this one has them stumped.
Bob