PLEASE HELP A/C Problem

[jwkwak3]

Please HELP. I have a 2002 Expedition Eddie Bauer Edt. I have the EATC and when I press Max A/C all the air blows out the defrost vents. I have replaced the vaccum hose under the hood and it did not fix the problem.
Here is what I know I have watched the blend door actuator and when I press any other setting the plunger will move and close the door to move the air to the proper location. However when Max A/C is pressed the plunger move the air to the defrost vents.
Question is it my EATC or am I stuck putting it in the shop to locate the actual problem. One other note is that I have 5 vaccum lines leading from the EATC is the correct amount because I have one open hole.

 

[KWT2000]

to the rest of the controls work when not on max a/c like vent/defrost/floor??? and regular a/c works ok if so it will be the brain of the system im not sure if it can be reflashed or if it has to be replaced

 

[jwkwak3]

Yes all the other controls works. The buttons I have are as follows
Max A/C Vent, Pannel/Floor, Floor, Defrost. Everything works except Max A/C.

 

[KWT2000]

i would get it into a shop and let them diag it... im still thinking it is the brain of the system

 

[jwkwak3]

When you say brain are you refering to EATC or the computer. I ran a diagnostic on the EATC and it showed no codes

 

[KWT2000]

the EATC no codes doesnt always mean there is no problem. also can you see if the recirc actuator and door are moving since max a/c is only a recirculating function

 

[jwkwak3]

Will have to check the door and actuator(if I can find them) I just went to the Junk Yard and purchased a used EATC for 75.00 gonna try that. The only door I know of is at behind the AC vents and I can push on it and then the ac will work

 

[supermario]

What is the EATC? Becus my bro 2001 Eddi Bauer does the exact same thing. But his started blowin the cold ac air through the defrost vents once in a while, but now its starting to blow the ac out the defrost everytime.

 

[KWT2000]

EATC meand Electronic Automatic Temp. Control

 

[DeltonaExp]

I have a 99 EB. mine does the same thing for a couple of minutes then swwitches to the vents. I figure its just to cool the air at the hotest points first (top of the truck) then the rest of the truck. Did you let it run for a while to see if it does start goinng through the vents? I would be interested to find out the out come.

Maybe mine is starting to develop the same issue as yours???