AC Air Mix Damper Motor Issue?

[jsa75]

I have a 2002 7.3L F250 Super Duty. Recently my AC has been acting up. For a while there I had to play with the temperature setting knob for a while before I could make it switch back and forth between heat and AC. Now it seems to be permanantly stuck on heater mode (when I have the knob turned all the way to the coldest setting the heater still blasts). I am assuming that the AC itself is not broken, but rather an issue with the air mixing device. Does anyone have any experience with this problem? How much effort does it take to fix? Thanks in advance. I live in central Florida and it's starting to get HOT!

 

[DaveBen]

You probably have a bad vacuum pump or a leaky vacuum line. I just helped a friend diagnose his. Bad pump. the heater defaults to high heat and defrost. If yours is not running in defrost, then this is not your problem/solution.

Dave

Dave

 

[jsa75]

You probably have a bad vacuum pump or a leaky vacuum line. I just helped a friend diagnose his. Bad pump. the heater defaults to high heat and defrost. If yours is not running in defrost, then this is not your problem/solution.

There is no issue with it only running in defrost mode. I can get it to blow from the floor or from the console vents. There is no issue with that control, but I will not rule out a bad vacuum pump/line.

 

[JLDickmon]

I have a 2002 7.3L F250 Super Duty. Recently my AC has been acting up. For a while there I had to play with the temperature setting knob for a while before I could make it switch back and forth between heat and AC. Now it seems to be permanantly stuck on heater mode (when I have the knob turned all the way to the coldest setting the heater still blasts). I am assuming that the AC itself is not broken, but rather an issue with the air mixing device. Does anyone have any experience with this problem? How much effort does it take to fix? Thanks in advance. I live in central Florida and it's starting to get HOT!

the blend door is behind the radio.. pull the radio and start the truck
flip the temp knob to full cold.. if the door actuator swings (it's electric), you've got a door broke loose in the box, and the box needs to be replaced (sorry, but there is NO fix for it).

if it doesn't swing on it's own, twist the actuator arm to run it to "cold" and immediately pull the electrical connection so it doesn't re-home itself when the truck is shut off.

these things are a bastard to change, you have to pull the dash to get at ONE screw.