Ford Repair: 1999 Windstar h/ac air flow problem VIN 8th=4 (3.8), little holes, factory radio

Question
Behind the radio/heating and air conditioning controls, I can hear what I would guess is a vacuum operated flap or gate that cycles constantly.  What I mean by cycles is, it moves to position A, but it can't stay there .... it returns to position B and tries to go to position A again.  Over and over.  Never stops.

Answer
Hello Nick,
   The noise you are hearing is the Blend Door Actuator. It's a little plastic box about 4" across, mounted to the HVAC case assembly. Access to it is gained by removing the radio, and it is mounted with 3 or 4 screws with 5/16" heads. One of the screws is actually easier by going underneath the glove box area(sometimes there is a panel to drop down. The factory radio requires an inexpensive set of special tools, little hooks that are inserted into the little holes and pushed outward and pulled on at the same time. I've seen coathangers used, but it is way more difficult. The blend door actuator(sometimes called a motor), is about $65 and you have to get it from the dealer. About an hour or so is fair clock time a shop to charge.
    I hope this info helps you, and I'm sorry for not getting back to you sooner. Good luck!   Shaun.