Not sure how to label this issue, but I have two Ford's with the same issue. When I switch from heat to cool or vice-versa, the temperature does not change. After a few minutes I can rotate the **** back and forth and it feels like it catches and then changes temperature. This is happening on my 1999 F-150 and a 2003 Escape. Any help would be appreciated.

 

See if the **** is stripped, a very common failure.

 

The **** appears to be okay, it seems like the unit is not getting a signal to change temperature unless you cycle the **** a time or two. It is almost like you can feel something open when it does change. Once you get past that it works fine hot or cold?

 

The temperature control is a simple variable resistor that sends a signal to the blend door actuator module. If the shaft of the control does not rotate smoothly, then the control is probably bad.

Steve