I have a 1998 Expedition that has an aux. heat/ac system. I am getting cold air in the front when heat is selected but getting heat from the rear system. Someone told me that the blend door acuator is probably stuck. How many blend door actuators are in the system? Which one would be bad? Where is the actuator located if I wanted to replace it? I was told that the actuator may not cost that much.

 

There is one blend door actuator for the front unit and one in the rear for the rear unit. The front one is located on the bottom of the case on the passenger side behind the valence and the floor duct. Pull the center floor console and the valence and the actuator is held on by three or four screws.