Weird blend door?!?!

[JJP1351]

Ok. all summer been dealing with heat on long drives coming from vents even though controls are set to cold. Yes there the dial kind. Finally cut open the dash, blend door is pinned wide open and don't wanna move. Hmmmm. Start the truck, blend door closes, swings half open, closes then wide open and stays no matter what the I do to the control. WTF! Any ideas? Can't find any posts on this problem. I'm pulling my hair out on this one.

 

[tcwaltz]

The blend doors are activated by vacuum. There is a line that travels through the firewall and inside. First make sure you have no vacuum leaks at that point. In many cases you may have a hole worn through a line. I had a rubber line that was cracked badly (this is on the passenger side) the line going into the firewall is thin and plastic.

If that is all in good shape you likely have worn out 0 rings in the controls. There is several videos on youtube on how to fix this problem. I currently have this problem with the automatic air on my 2000 and I just havent' gotten around to doing the repair. My symptoms are the AC blowing for defrost and not coming out of the dash. If I accelerate shut the AC off, then hit automatic I have a 50/50 chance of it working right. Usually it takes no more than 2 or 3 attempts to make it switch. I also notice my blend door doing odd crap when the engine idles rough which I assume is related to the vacuum leak.

 

[JJP1351]

The blend door for my heat/cold. The switcher is run by vacuum. The blend door is a few wires. Thanx for the effort tho. It's gotta be my blend door motor. Cuz it won't move at all now.

 

[Bedrck47]

Attached is the wiring diagram for your 2001 expy

 

[JJP1351]

Thanx Bedrck. But, already knew its wired. Just thought out of ALL the electrical problems these Fords have, someone would have had the same problem and could verify a fix. But since its on its last season more than likely, i'll just break the actuator motor and just use a lever thru the dash to control the blend door. Not putting more $$$ into this thing when I can redneck it.