A/C control head/blend door problem that seems to have the dealership and tech support stumped. Mode control doesn't work. They replaced the control head and actuator. Still no luck. They recalibrate the head but as soon as you change from a/c vents to defrost or heat it freezes up. After a while it will revert back to a/c but then will not change to anything else. The dealership has three other control heads in the back with the same problem. Mine is now on its way to California for testing. This seems to be a trend, from what I have read on the net, common to the XL7 and Chevy Equinox which I've been told use the same control head. I'm looking for a recall on this vehicle.