i have a 2005 F150 fx4...the air cond blows out the front vents like it is suppose to, but when i switch to heat the heat still blows out the front vents, not the defrost vents or floor. Sometimes when im driving i could hear something and it will switch for a min, but as soon as i turn on the air it gets stuck again. I read somewhere that there is a TSB for this problem..does anyone have the correct TSB....

my ford service dept told me that my extended warranty might not cover the problem if something is blocking the blend door, but if its defective it will be covered...which makes it a roll of the dice...dont know if im covered or not, and they have to take apart the dash to tell me one way or another...