 Bad control head
The problem is with your auto climate control head. pull out the control head and observe the vacuum lines that attach to the rear of the unit. They plug in to the electric solenoid plenum controller valve. It is this valve that causes all the problems and Ford motor company will not sell you the part or offer it as a dealer serviceable item. I exhausted all avenues attempting to find a reasonable solution to the bad control valves, Ford refuses to help in this matter.
Solution:1. remove the vacuum line unit from the control head
2. Remove the electric solenoid valve pack from the control head.
3. Holding the valve pack with the vacuum lines facing away from you remove three solenoid valves except the one on your left side nearest you There are 4 all together. Make sure you remove the plungers.
4.Fill in the holes with some putty that hardens on all three holes.
5. Remove the forth solenoid valve and then remove the plunger and then replace the valve back on the valve assembly.
6. Wait until the putty hardens and then replace the valve back onto the control head, and then return the vacuum lines and place the control head into the dash.
You will have full dash vents open along with temperature control for heat and ac. However, nothing else will operate and I have found out that all you really need is the dash vent control.
Ford wants $800 for the other solution and it waits to fail again. | 
