Temperature is controlled via an electric actuator motor.
See "Related Questions" below for more all about Windstar rear heating / cooling systems.
thermostat stuck
repair the heater hose.
The most common reason the heater is blows cold air on a 1999 Ford Winstar is a bad thermostat or blocked heater core.
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 block heater plug in on a 1998 Ford Windstar is in the engine compartment on the passenger side of the vehicle. When lifting up the hood, look on the left for a small hose that is coiled up at the very front, above the passenger headlamp. The block heater itself is plugged into the front of the motor on the passenger side.
Replace freeze plug in a 1998 ford windstar ?
A 1998 Ford Windstar would use refrigerant 134a
Maybe it's bad. Have you tried changing it? Sound logical to me.
my 2001 ford windstar is still overheating even though i changed out the thermostat. what could it be?
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.
heater windstar ford
Heater circuit fault