What to do if changed thermostat still running hot heat blows warm then cold air on a Ford Windstar?

Answer 1

The water pump can also be failing - the fins on the impeller wear away, greatly reducing the movement of the coolant through the system.

There is a actuator that is behind the radio in a Windstar. This actuator is air operated that opens and closes the heat/air conditioner door. This is the slider control that you adjust for colder or warmer under the heat / air conditioner controls. Sometimes this valve goes bad and is stuck on the cold air, thus not letting in any heat to the front. There are 2 different valves - one for the front and one for the back. You can buy the actuator valve from Ford for about $ 40 to $ 50 dollars. You will need to buy a radio removal tool ( any automotive store, Walmart, etc..). This tool has 4 prongs that you press into the 4 holes on the radio and it unlocks the clips. Remove the radio ( unhook the antennae cord, power supply, speaker hookups and pull the radio out). The actuator can be seen after the radio removal. Unhook the actuator and replace with the new one. Reinstall the radio.

See "Related Questions" below for very detailed information on replacing the temperature blend door actuator *motor* (it is NOT a valve - it's a small motor).

In regards to the problem, I would suggest the engine coolant / anti-freeze level is low - and/or there's an air bubble in the system.

Keep checking the coolant, making sure it's topped of with the proper type and 50/50 mix of coolant.

See "Related Questions" below for more