xbstw, the temperature control is the final piece to the puzzle I haven't figured out yet. At first I thought it would be easy, since the heat blend door is moved by a servo controlled by a logic board.
The logic board tells the motor how far to open the blend door based on a voltage input from the temperature dial. It's basically a rheostat (potentiometer) that sends 20 or so different voltage levels to the logic board.
Getting Fusion Brain to emulate the different voltage outputs is the final piece of the puzzle.