easy actuator removal
My situation was like flbuilder1 - no antifreeze smell, but no heat either, not even intermittently, regular control not automatic. I remembered that last summer I had some water on the passenger side floor, probably from the outside condensate drain plugging up. The water apparently got into the door actuator and corroded it to death so---
I looked at all of the articles on removing the actuator, generally it is termed a tough job, but doable. A couple of the posts indicated that cutting the duct below the actuator motor was the answer, but many people are reluctant to take a saw to their truck. After looking over the situation carefully, I decided to go with the saw option because the passenger end of the duct is screwed up into the heater box body and I figured I could tape the cut portion back together and get a good seal. It was the right decision, whole job takes about an hour.
Carefully remove the kick plate (press fasteners) and you can see the duct at the floor, the white actuator motor just above it. There is only an eighth inch clearance between the actuator and the duct, and the stem that fits up into the blend door is about 1.5 inches long.
Cutting the duct on the left side just before it makes a slight upward bend will remove the duct from your access area after you remove the screw up into the heater body on the passenger side.
Now it is just a five minute job to remove the three screws holding the actuator into the heater body, drop the old actuator assembly down and out, and install the new one. The stem that goes into the blend door will only install correctly due to its shape, so no worries.
I used an aluminum duct tape to seal the cut area, but regular should work as well, just maybe not as durable. Cut a strip of tape about 16 inches long, slide it between the floor tab and the still mounted duct edge, then slip the cut off duct piece back into place and pull the tape ends around it to complete the seal. Put the passenger side screw back up into the heater body, reinstall the kick plate and your done.
Then pull the kick plate back off, plug in the actuator wire harness and reinstall. (Optional)
BTW, my local Ford dealer (Arizona) wanted $88 for a new actuator so I ordered one from a parts dealer on this site (Washington state) - total cost including shipping, $46. Easy button