Yes you would think heat means no air. However a room full of ford engineers deceided that it would be nice to design a blended air. They named it blend air system.
Their theory was to mix ice cold air with warm air to reach the desired temp the operator wanted a couple mins faster. Bad idea.
So now back to the blend air door yes it can be open and yes usually this is an electrical prob the elec door operator has failed so up under the dash on the heater box you will find this part actuate your heater controls and watch it see if it is only partially closed.
As far as the a/c I unplug mine every winter no prob
Tuesday, September 28th, 2010 AT 7:50 PM