Heat stuck in defrost position

[mf7365]

I recently started checking out this sight when I rebuilt my 4404 T-case. The info was great and helped tremendously. I got it done just before the snow. So, my problem is, my heat is stuck in the defrost position. Regardless of were I position the selector knob, it won't move from defrost. I can still select the air conditioning which will then blow cold air, but I can't get the heat to go anywhere but straight up. It was working fine, and then nothing. What kind of solution if any is available. Thanks.

 

[Cobraguy]

You have a loss of vacuum to your HVAC system. It can be under the hood or under the dash. You just need to start tracking your vacuum source until you find the problem. It could also be a bad vacuum reservoir that is located under the engine air filter box.

 

[mf7365]

What would I exactly be looking for as in regards to tracking a lack/loss of vacuum? I was wonder how exactly the knob/selector worked. Is it simply an electric connection behind the knob, as I can't imagine it is cable actuated.

 

[team]

check out the diagram at the top of this page

http://www.explorerforum.com/forums/showthread.php?t=192842&highlight=vacuum+diagram