I still need help with the heater problem. A 99 exp. that blows cold air and rear unit works fine. Does anyone know where the blend door actuator is located? Are there any heater components under the hood that might cause this problem? Thanks, Bart

 

It is located on the bottom of the air distribution box. You will have to remove the floor vents for the heater and then on the passenger side of the driveshaft tunnel you will see a box about the size of a cigarette pack.