My windshield defroster isn't blowing out any air but the side ones are. I have read many threads about only the defroster working and it has to do with the vacuum lines, but is my problem due to a vacuum problem? The AC isn't currently working, but I suspect that that is just a leak. When I flip to defrost, I can hear a pop from a baffle, but nothing really happens. I could use some help as it is going to start freezing. Thanks!