HVAC Temp Control Clicking Unresponsive Repair
 

This is a real common problem especially with temp control that seems to vary or be unresponsive as this is more common in the F150's but this applies to both 2007+ Expeditions and 2004+ F150's. In this video I show you how to get at the blend door actuator and change it out, hope this helps.

Ford F150 & Expedition Temperature Blend Motor Clicking - YouTube