you probley have a vacume leak due to a broke or craked hose u should take it to a shop for a pressure test if u do not have a vacume tester.
so far everyone points to actuator blender failure but check for vacuum leaks first
This "flap" is the temperature blend door which directs air over & through the heater core.The "Related Questions" below are intended to help explain some of the basics of Windstar heating/cooling functions and terminology.That should help in the investigation of the specific problem on the vehicle, and ultimately leading to a fix.Start with the "Where is the heater control valve located on a Ford Windstar" question and then move on to the "What could cause a Windstar to have no heat - or not be able to adjust the temperature"
When there is a problem in the vent system it defaults to defrost setting. Check the doors & vac supply
The "bleeder screws" that come to mind are:Brake bleed - found at each wheel caliper / wheel cylinderEngine coolant - NOT found on a Windstar engine. Cooling system bleeding/burping is basically through just running the engine with the coolant reservoir cap off.
Air bubbles in the cooling systems usually means that the head gasket has gone out. As with most auto mobiles, air in the cooling system means exhaust is getting into the cooling system through a break in the head gasket. A break has probably occurred between the cylinder ring on the gasket and on the pressure stoke is passing through to the water port in the block at the top of the cylinder between the head and the cylinder indicating a break has occurred in the gasket.
The way you get the Windstar through Marta is to plan ahead. Know the route that you want you to take, and try to travel during the day when traffic is not bumper to bumper.
You have vacuum line leaks somewhere.
If the problem is to help engine cooling through the direct transfer of heat out of the piping, the aluminum will be superior to the silicone piping by far. Aluminum is one of the best materials for the conduction of heat.
The coolant pump draws coolant from the radiator and circulates the coolant through coolant jackets in the engine cylinder block and the cylinder heads. The coolant is then directed back to the radiator. The system directs some coolant through hoses to the heater core in order to provide for defrost and passenger compartment heat. A surge tank connects to the cooling system. Pressurized coolant continuously flows through the surge tank and the process repeats
In many cases leaves can cause smoke to blow through the defrost of a 1990 Ford F 150
Adiabatic cooling deals with the cooling of parcels of air as they rise, or are forced up, through the atmosphere.
Could be a vacuum problem--either broken or disconnected hose or bad vacuum motor under dash or coming in through firewall Defrost is the default position for this system