Hello I'm having heat problemes. so far i flussed the system, still having no heat, Changed radiator and heatercor,Changed thermostat,Changed heat sensor,Now pleanty of heat acording to gage but still cold air coming out of heater in van temperture rises and droppes quit fast. Don't know whats next please help a fello mechanic. thanks Richard C Betty Sr

You will need to replace the HVAC blend door actuator, it is stuck and not allowing warm air to go through your vents. Inside this unit is a circuit board, motor and small plastic round gears. The gears then rotate the actuator, which in turn opens and closes the damper allowing the air to pass through the heater core. What happens is some of the little teeth break off creating a gap on the gear wheel. This gap prevents the gears from driving the actuator shaft. Click on the link below to view a replacement door:

http://cgi.ebay.com/ebaymotors/1995-Ford-Windstar-Temp-Control-Motor-Actuator-Manual_W0QQcmdZViewItemQQhashZitem3c93d45565QQitemZ260178204005QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

Have you checked the position of the hvac door inside the heat box? those systems work on vacuum alot so it could change with engine rpm, so that might be where your problem is comin in.

Did you check the vacuum source of all heater controls inside the dash? maybe the actuating door valve has a leak due to an air line. also the selector mode switch could be bad