66 Cuda HVAC control problems

I am restoring a 66 Barracuda 273 and am having problems with the AC controls. Here is what I've checked so far:

- All vacuum actuators, and AC, Heat and Defrost doors are working when hooked up directly to vacuum lines. Push buttons move freely in and out. Heater valve control cable and valve itself work. Fan switch and blower work (although blower motor is on last legs)


However, when I hook the vac lines up to the dash controls, everything works except when I push AC or MaxAC, the door for the AC opens, but after that it will not close. If I push Heat or Defrost, the AC doors stay open, with no air to heat or defrost.

Any suggestions or comments would be appreciated. Thanks