Update on the heater fan. Yep, when turned to high it blew the fuse. They had the RV for almost a month...I told them I was in no hurry...on hind sight that may be why it took so long. It was the fan control assembly. They replaced the entire controller and the wiring all the way to the power source. It seems there is a capacitor and fuses in the wiring and it's easier to change the whole thing than to try to find the exact part of it that is bad. Part of why it take so long is under factory warranty, the dealer has to diagnose and remove the old part before ordering the new replacement. He said they receive their parts order from Thor every Wednesday.
They told me they are seeing this on the Miramar, Challenger, Windsport, Axis and Vegas. They are not sure what is causing it but seems to be associated with the high fan setting when using the heater, not the A/C.
He also said if I never used it on high it would have been fine. That didn't seem like a good option for a new rig.