Fixed. Thank goodness for Winnebago Service folks, Winnebago electrical schematics, and Evans Tempcon online troubleshooting documentation.
To summarize, no power to the Evans system. Per the Evans schematics, power is fed from the F53 chassis to the dash selector control, and distributed from there. The big question was: what is the source of power from the Ford F53 chassis? The owners manual is silent on this.
Long story short: Winnebago has taken power from the Power Distribution Box (located on the firewall under the hood) fuse labeled "Blower" (fuse #23, 40 amp), and directs this to a 25 amp breaker inside the cab. This breaker is located in a panel below the inside fuse panel (the fuse panel is located left bottom of the driver's side, by the left foot when driving).
Now the tricky part. The above "Blower" fuse feeds power through the blower relay. A relay has 2 feeds: 1 is to energize the coil in the relay, and 1 is the main power feed. Once power is introduced to the energize the coil, this closes the contacts in the relay so that main power passes to the device fed by the relay. In my case, the ground wire from relay coil became disconnected (I discovered the loose wire behind the speedometer panel after removing the plastic dash cover). Since the relay did not energize, power wouldn't pass from the "Blower" fuse to the Winnebago 25 amp breaker which supplied power to the Evans unit dash panel.
Whew! So, the source of power to the Evans unit is the "Blower" Fuse in the Power Distribution Box. The Ford owners manual does not note this rewiring. The only way to decipher this rewiring by Winnebago would be by investigating the electrical schematics at the Winnebago website.
I will say a big thanks to Winnebago taking the time to respond to my inquiries by email, and posting the Chassis Drawings for my 2011 Winnebago 32K as pdf files on their website. This no doubt saved me a pile of money at a service center.
I post this so others that may have a similar problem will be aided.
Regards.
2012 Winnebago Vista 32K
2011 Honda CRV Toad