I just bought a used 2015 GMC Sierra 1500 ale crew cab. 5.3 eco tech engine. My issue is that when I press the front defrost button it just blows through my vents. I’ve read that there is blend door reset by pulling out the fuse. I’ve tried that but with no luck. Maybe someone has better instructions for it or possible the directions to replace the actuator for modes of air flow. Thank you