I have a 200 ford excursion that is having 2 issues with the a/c. First, when you accelerate it seems like the blower switches from dash vents to defrost. Once you let off the gas or maintain a steady speed for a little while it will go back to the dash vents. Second, the rear a/c is cold but the front will only blow warm. I have removed the blend door and checked that it is functioning. Everything looks ok, but I have seen the fix with the nail on another post but I don't think that applies here. With the actuator in place the air can be adjusted from warm to hot. I removed the blend door and made sure it will adjust while not under the dash. The arm turns from right to left to full extent. I took the arm out of the housing and put it in the hole that it goes in and was able to manually turn left to right and could hear the door open and shut and the temp would go from warm to hot.

If anyone has any other ideas, I would appreciate them.