The blend door is vacuum controlled. Any vacuum leak in the engine system can cause the door to not function properly. Check this system first. The door could be physically sticking but a vacuum leak is a more common problem.
my 1999 winstar was doing this and it was the blend door
If by "heater box" you're referring to the heater core, we've got you covered with the "Related Questions" below.Be sure to review the questions regarding the blend door and blend door actuator motor - other very popular heating/cooling parts in the Windstar
If you are having any heating or a/c issues in your Windstar, be sure to check your blend door for functionality FIRST. The most common issue with heat or A/C in the late model Ford windstar is a broken blend door. A broken blend door actuator is almost as common as a broken blend door itself. Typically, the fix requires disassembling the entire dash and replacing the whole plenum box, which can be a costly repair.
If you are having heater/air conditioning issues in your Ford Windstar, the first thing to check should be the blend door. Broken blend doors are the main cause of heating issues in this vehicle. The Blend Door actuator on the Ford Windstar can be found by removing the glovebox. A broken blend door actuator is almost as common as a broken blend door itself. Typically, the fix requires disassembling the entire dash and replacing the whole plenum box, which can be a costly repair. Linked here is a video from www.heatertreater.net demonstrating how to access components of the plenum box for repair without disassembling the entire dash
Not a whole of symptoms to work with here...The most common cause of "... heater not working..." is a failed temperature blend door actuator motor.See "Related Questions" below for more
There are 3 primary questions about Windstar heating & cooling problems: * Temperature blend door actuator motor replacement * Heater core replacement * Various causes of 'no heat' problems See "Related Questions" below for links
Sounds like the heater core may be plugged up or the heater damper door is broken. See "Related Questions" below for more
This happened to my 95 Windstar-I just replaces the fuse for the air mixture door. On my 1999 Ford Windstar, the blend door itself broke. This repair is more costly and more difficult, perhaps $700 to $1000 to replace. I just tied a shoestring to my blend door. When you insert the blend door actuator if there is no slot for it the door is broken and you are up sh... creak. Hope it is the former. Another option is from a company called HeaterTreater - a method to repair a broken blend door without removing the dash. I haven't tried it, but the ideas behind it seem to make sense - and they have lots of videos showing the processes. http://www.heatertreater.net/Windstar%20Listing.html
Before replacing the thermostat or any other component of your Windstar's HVAC system, be sure to check your blend door for functionality FIRST. The most common issue with heat or A/C in the late model Ford windstar is a broken blend door. A broken blend door actuator is almost as common as a broken blend door itself. Typically, the fix requires disassembling the entire dash and replacing the whole plenum box, which can be a costly repair.
The "Related Question" below is an extensive discussion on the 1999-2003 temperature control valve / heater control valve. It is likely the information will be similar to the 1997 / 1998 Windstar
The blend air door is probably broken.
I believe you are looking for blend door actuator???