Low coolant? Bad thermostat? System airbound? Water pump not circulating coolant? Temperature control cable not adjusted properly?
If you use tapwater, you may feel cold but if you use a heater, you wont feel cold.
More than likely your heater core is plugged, and will need to be replaced
The most common reason the heater is blows cold air on a 1999 Ford Winstar is a bad thermostat or blocked heater core.
sounds like the head gasket ...same thing just happened in my 97 cavalier
Either the linkage from the temp control unit to the valve on the heater core (which is behind the radio and temp controls) or it is the heater core itself.
yes it can, but dont really recommend it. if your car starts to over heat and the heater core not there you can not use the heater fan to help cool it down, also if you live in an area where it gets cold you wont have no heat.
You will have only cold air coming thru your heater ducts if your core is defective.
some possibilities are. low coolant level, open thermostat, pluged heater core,
In the plastic jug on the left firwall be sure to fill it to the "COLD" line if the engine is cold which it should be or you would not have opened the cap.
the heater blows warm air when fan is on low but blows cold air when fan is turn to higher setting
Check to insure that the engine coolant is full and the thermostat is not stuck. Without the heated fluid from the engine the heater will always blow cold air.
Was put in Katrina workers way!backwards..deal with it!