i printed out devils advocates instructions on rebuilding eatc module, but when i took it apart i found no o-rings. the little hex plunger has a rubber stopper shaped piece on the end of it. i put o-rings they fit over the rubber end piece and went inside the tube fine. put every thing back together and it blew out the defrost only. ac blows cold, works fine in town but when i get on hwy it switches to blowing out defrost when i let off of accelerator it goes to panel where it should be blowing.........help i'am losing my mind..lol

 

I have this same problem, only reversed since I "rebuilt" mine.

 

i'am new to this site,tryin to navigate. i hope someone out there can help. its difficult to change o-rings when there are none