For the heck of it, replace fuse #15 in the engine fuse box. That was part of the problem that I had when my car was blowing warm air. Fuse 15 provides power to the center pin of the duo valve.
My other problem was a potentiometer in the climate control unit. The fan speed would work sometimes but not others. Thanks to pizzaguy's advice I was able to find the problem. He also rebuilt my climate control unit.
I rebuilt my duo valve for the heck of it. All is working great now.