Anyone know why the Air vents in my rear 03' STR are not blowing Air fully through the Rear passenger vents? It blows cold air very slowly but not fully, like something is restricting it. Any thoughts on what it could be?

Thanks

UPdate: Found out that the middle knob was jammed inside so I had to use a flat head and flick it in open position, now blowing air like it suppose to. :P