Besides a bad alternator that could possibly affect the air flow that goes through the vents properly, what else would be the cause for the air flow not to work properly while turned on and on high setting!?! It’ll seep out a little air while in drive mode but just barely enough to warm the interior cab while setting is on the highest level. But while in park and idle no air whatsoever goes through the vents. C’mon all your armchair mechanics lets hear what y’all got to say about this!?!