Whistling in the vents, mazda b2500
Hey all, first tech post here. I just got a 99 mazda b2500 over the weekend, nice little truck in pretty decent shape. Thing is, every time the truck goes over 40 the passenger side vents start making this whistle. By 55 or so, its LOUD. I was fiddling with the air controls, no setting/temp/fan speed seems to make a difference. I did notice that if I opened my window it would go away. The old owner told me about this problem, i figured it wouldn't be a big deal to fix, but it is really annoying and was wondering who's run into this before? I was thinking it could be something jammed in the air vent, or a leak in the air vent, or some weatherstripping-related issue somewhere. Any ideas on where to start are appreciated.