This isn't a horrible problem, just a pain in the neck. When you switch the blower vent control switch to head, it blows out the windshield defogger. The Feet works fine, but even Bi-Level blows out the defoggers, although with feet. But sometimes, air blows out the head vents, mainly when the car has been running for a while. Then, after a minute or two, it would go back to the defogger.