I have noticed over the past few months that my floor vents don't work. I assumed it was the mode 2 door that would need to be replaced. However, this past weekend, the floor heat started working. I had the selector on defrost for most of the trip to SD and then changed it to dash vents part way there. When I started my trek home, I set the selector to defrost again with low fan speed. Part way home, I noticed my feet were getting warm. When I stopped for gas, I noticed that the defrost was not blowing but the floor vents were. I tried changing the settings and switching back to see if I could get the defrost, but nothing worked. When I got home, I turned the fan off and then changed the selector to defrost and floor. I waited until the motors for the vents to stop and when I turned on the fan, I got floor and defrost air movement. I am unable to get the defrost and floor heat with the fan on. I don't know what motors or doors I need to replace. Any advice would be helpful. Thanks.