I can not get my blend door actuator to move when I adjust the temperature selector. I have replaced the blend door actuator, and the selector switch. What else could be wrong?

BTW this is on a 06 F250 diesel with manual HVAC system

 

Did you check fuses? Get a wiring diagram and start tracing the power.

 

Have a 00 EX and the rear selector works great.

Front manual selectior is not working fan and temp work but the selector is not working. ONLY blows on defrost. Will not change output to pannel or feet.

Took out the glove box and the arm moves a bit but not much at all.

Thinking its the HVAC controller. Anyone else have this problem? Dealer wants 90.00 to let me know what MAY... be wrong.

 

have you checked the shaft for the blend door. It's made of plastic and known to break.
here is a site that has a fix for it. 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, Ford F250, F350, F450, blend door auto AC heat replacement part
Other wise if it is broking you would need to pull the dash and hvac box.

 

dont think its the blend door.
Heat and AC work fine - they just only blow out of the defrost.
Im pretty certain that its the HVAC control on the dash. Just wanted to see if any one else had this issue and be sure before I order it.

 

Blend door was for the OP. For your concern it might be a vacuum problem you could get a vacuum hand pump and try that to see. If you have the Electrical HVAC you will have to check the wiring

 

If it is the auto climate control hvac controller, they have been known to cause that problem.I would verify it had a vacuum source to it before replacing. Wife had a mercury grandmarquis with the same box and had two in it before it was 4 years old. Ran into the lady that bought it from me during christmas and she mentioned having to replace it again

 

Check for a vacuum leak on the line feeding the controls. A lack of vacuum will cause the system to go to full defrost. Not sure how the lines are run on the gassers, but on the diesels, the line going to the controls is located on the passenger side in the area around the blower motor. IIRC, the color of the line is white.