Shadowkahn1234

Hey everybody. It's been quite awhile since I have been here. I've missed you! I have a question that someone here can surely answer. I have a vent under each of my front seats. No grill, no cover and most importantly, no air! I read somewhere that these have to do with the defroster but nothing I do will get anything to come out of them. They're roughly 6 inches wide by 3/4" high and appear to go straight toward the front of the seat then down. If these are vents, how do I get air out of them in my 2007 F150 SCAB? If they are not vents, then what in the Ford world are they?