Well during the test drive the air coming out of the center vents was cooler, but not cold (note: pressed button to close off outside air during this test). Then I noticed both side vents have warm/hot air coming out of them (noticably hotter than the center vents). Cycled through modes with temp 'knob' set to as cold as I could rotate the 'knob' (potentiometer, variable resistor?) in the blue section:

1. Defroster: blew *extremely* hot air against the windshield
2. top and middle vents: blew cool air out top and middle vents (seemed like fan was on extremely slow speed)
3. just middle vents: blew cool air out middle vents with a bit more gusto

I could switch the temperature setting back and forth between hot and cold and there was a noticable change, but hot was extremely hot and cold was cool.

What is the chance this is related to the duovalve?

10-4 on the wiring. Will clean that up this weekend. So what was the fuse on the blue relay for if not for the AC?