No Defroster

[crawdad]

I hope some of you guys can tell me what to check or look for. I'm not getting any air at all through the defroster . I've taken the glove box out and some of the air ducts to see if a vacuum line might be off, but I couldn't find anything. Everything looks ok, but admittedly it's a bear trying to find something underneath that dash. I know some of you folks have gone through this before, but I couldn't find anything by doing a search. Any help would be very much appreciated.