Ok so recently (just in time for winter) my truck is only blowing out defrost.
Now things ive done. The white vac line under the hood was shot so i replaced about a foot of it with new line.

Recently i took out the AC unit and replaced with a bypass pulley if this could affect it.

When i move the vacuum control right above the passenger foot well the air will come out of vents.

I check the lines for leaks and cant find any.

Anyone have places to look ?

(pic of little vacuum control that will let me blow out of vents manually)
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[IMG]<a href="http://imgur.com/Lm2jzAy"><img src="https://i.imgur.com/Lm2jzAyl.jpg" title="Hosted by imgur.com"/></a>[/IMG]

 

Lack of vacuum will default to the defrost.
Have you checked the vacuum source and its "T" and check valve going to the vacuum tank on the side of the box?

 

If it were a dodge I could tell you with 100% certainty it is the diverter door - but I dont know much about fords - sorry, still learning.

 

Can you by any chance tell me how and where to check for vacuum. ?

 

You may find this useful:

 

In what order should i check things to diagnose the problem ? that is a useful chart !

 

Start with the vacuum path from the manifold to the check valve, HVAC vacuum reservoir, then onto the control panel.

 

any word on where all that sits ? inside engine bay passenger side ? pics of it ?

thanks !

 

The vacuum source starts on the intake manifold. Referencing the diagram above trace out the vacuum source and path of the black hose. One end starts at the intake manifold the other ultimately terminates at the HVAC control panel inside the truck.

 

AC Vacuum tank:


Vacuum line and check valve:


Vacuum source:

/

 

I knew you had a few pics somewhere Bill, thanks!

 

Ok so i looked into it last night. Started tracing some lines. And found alot of problems clearly from the previous owner. Can you guys clarify what the hell he did here. Also i removed the AC pully and let the lines sit there idk if that would effect vacuum.
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<a href="http://imgur.com/5wwHDTG"><img src="https://i.imgur.com/5wwHDTGl.jpg" title="Hosted by imgur.com"/></a>

<a href="http://imgur.com/s4GVQdb"><img src="https://i.imgur.com/s4GVQdbl.jpg" title="Hosted by imgur.com"/></a>

 

Had the same prob with mine but I just replaced a few lines and its fixed

 

the real problem now is the previous owner messed up so much of the vac line im confused.

 

I think the center photo goes to the vacuum can that is more than likely missing.
The top photo looks kinda normal but can not tell from the photo.
Not sure what is in the bottom photo unless it is the purge valve.