Ok guys, I was one of the many that had a blender door go out. It seems like this is a widespread problem with no answers on how to fix it. Of course, mine was the driver's side, which according to Ford, requires the entire dash and everything to be removed to replace it. Not wanting to spend the cash at the dealer, I decided to just take the thing apart and either fix it, or FUBAR it. Well, I did the former.
It turns out that all three of the motors are relatively easy to get to. I removed and inspected all of them, replaced the driver's side temp control, and had the truck back together within a matter of hours, and I'm slow. I am going to focus on the driver's side temp motor, as there seems to be the least info on it.
First of all, the location of the three doors. The passenger's side temp control is behind and to the left of the passenger's side airbag. It is the top circle in the pic. The driver's side temp control is right above the trans tunnel, and below the center stack, shown in the bottom circle. The motor that switches between the dash vents, defrost and floor is on the driver's side, directly behind the panel that houses the adjustable pedal button, in the far left circle. All have a black plug with a red lock. the red part has to be pushed away from the motor before the plug can be removed from the motor.
I did not know were the thing was, so I started tearing apart everything. However, to get to the Driver's side temp control blender motor, you can simply removed the center of the dash, the part that surounds the radio, and the lower section that holds the cupholders. Just a few 7mm screws hold it in. Here is a pic of the lower blender door.
It's kind of hard to get to, but it's possible. You will notice that the floor vent is cracked, I did that thinking I could remove it. Not quite. But, you can push it down, which gived you just enough room to remove the back 5/16" screw. And as you can see, the front 5/16 screw (the silver one) is easy to get to. I used a thick flathead screwdriver to wedge the floor vent tubing down, and used a boxed end wrench to remove the screw. It was slow going, but I did it. Now that I know how to do it, I bet I could have it done in 30 minutes.
I hope this helps someone!