Heater Problem
 

Have a 1999 Ford Windstar Van. Heater has stopped giving off heat--AC & fan work great, just no heat. Any suggestions.

What does the temperature gauge show?
If it is at least half way up , the next thing to do is feel the hoses that carry heated coolant to the heater. If they are the same temp there is a possible blockage in the heater core itself. If one is hotter than the other some heat is going someplace and then a check should be made to make sure the ductwork doors are working correctly. If the incoming air can't get past the heater core , get heated , then move on to the inside doors that direct the heated air to whatever function is selected on the controls
a door may be jammed ,locked in the cold position.
If the temp gauge doesn't go up to around half way up , the thermostat is probably stuck open and will need to be replaced. Not a big job if you have the correct parts and can do it inside where it is warmer.

Or the blend door actuator is out to lunch