That, or a vacuum failure/leak. The "default" position is "defrost" in case of loss of vacuum. Safety feature to keep the windshield clear. Yes, you may freeze and die, but at least you will be able to see the road.
The difference between genius and stupidity, is that genius has it's limits. A. Einstein
Last edited by Lazarus Truck; 05-09-2014 at 10:42 PM.