Both AC and Heat blow the same air.
Sounds like a flow flap or vacuum control head issue. The system uses 1 blower motor and one fan resistor. Both systems are intergrated to produce a BLENDED temperature. This means that to raise A/C temps originating at say 20 degrees to come out of the ducts at 45 degrees for cooling you need airflow through the heater core WHILE the A/C is on.
This is done with a blender flap. Hot air that is potentially matching the water thermostat (165 degrees) is expelled to blend with the 20 degree air to raise the discharge temperature to 45 degrees and up.
In winter, the A/C is engaged by design to keep the compressor lubed with oil. Usually this happens in Defroster mode, but through either Design or defect, may occur in heat position.
Now some of the Digital Climate control units have a Diagnostic sequence you can activate with certain button pushing combinations. Research Your Model, Year and then Climate Control Diagnostics on the internet. The sequence is something Dealers know about.
This Diagnostics would identify a malfunctioning Flap valve actuator.
I recommend people to visit a Salvage yard which allows you to dismantle a car yourself and see how the car is built.
Hope this helps and makes sense to you.
Jul 22, 2013 |
2003 Ford Taurus