thermostat stuck
A blocked heater hose could cause a leak. A stopped up heater core could as well. Or the connector in the Windstar could be cracked.
By overheating which will cause a change in the thermostat materials construction.
heater on at idle and will not blow warm air. when moving it blows the warm air from the vents. what will cause this
Take it apart to determine the cause. Only then you will be able to fix it.
The motor which blows air through the vents.
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"
Check the coolant level. Usually low coolant levels will cause this.
thermostat
A bad water pump or thermostat can cause an engine to overheat. A plugged (clogged) radiator or heater core may also cause an engine to overheat.
There are many reasons why a Jeep Wrangler is overheating. A leak in the radiator system will cause overheating. Too much pressure in the engine can cause overheating. A bad water pump or thermostat could cause overheating. The transmission can also cause overheating if it is leaking.
most likely your heater controls run via vacuum lines. cracked or broken lines could cause this.
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