Hi! After years of reading these forums, This is my first post. I have a 2009 E350 SD 5.4L that refuses to blow air from any vent. I have changed the blower motor, condenser coil, dash switch, checked all the vacuum lines, everything appears to be working fine. The blower motor spins well, and changes speed like it should. I had the entire dash out of this thing, pulled 3 mouse nests and thoroughly cleaned the vent system, I'm at a loss... Any ideas/help would be greatly appreciated! Thanks

 

This is only an idea and I'm not even sure if it will work.
With the blower motor removed, either use the vacuum side or the exhaust side of your shop vacuum and fit the hose end into one of the vent or heat ducts and see what comes out or comes back to the motor housing. Could get the whole family or maybe just the apartment building , but unless they built with cement , you should get / see something. Unless you have seen some of the work these little creatures do you would never believe it. If one of the air direction doors is jammed or broken you will find that too.. Don't forget to go in the other direction where fresh air is allowed to enter the blower housing. That should be up just under the wiper cowl, pass side.

 

Thats a good idea, I'll give that a try, and double check those doors. The only thing I haven't replaced is the electronic control on the side of the air duct under the dash on the passenger side. I also tried it with the condenser coil out and it works fine, put the condenser coil in and it doesnt work at all. And the coil is brand spanking new and clean.

 

Tried the shop vac and the air compressor at full go, nothin... guess I'm gonna have to tear this thing apart again and triple check for clogs and nests... Reckon the blend door actuator is the only thing left to change but I wouldn't think that would stop all the air from flowing. Thanks for your help!

 

My 2001 E350 has the same problem, no air from any vents no matter what I select. The fan was bad so I replaced that, thinking my problems were done, but I didn't get so lucky.
Over the winter I would get just a slight amount of air through the defroster no matter what I selected. Maybe this was just due to the fact that warm air rises.
I'm curious to learn what you find. If I get there first I'll post my findings.