Thanks for the update.
On the control panel assembly is the temperature control knob. The temperature knob mechanically operates a cable through a cam mechanism to adjust the temperature blend door. Temperature blend door is in the plenum assembly. When temperature knob is in cool position (turned fully counterclockwise), temperature blend door stops airflow to heater core. When knob is in the warm position (turned fully clockwise), air is directed through the heater core. When knob is in intermediate positions, heated air is blended with cooler incoming air to achieve desired temperature.
Since this appears to be a mechanic, look at where the cable connects to the blend door. Then move the cable. If you can see the cable moving at the blend door connection then most likely the blend door is broken from the connector.
If you are turning the knob and the cable is not moving then it may be broken at the control panel assembly knob. I would check there.
If it is not broken there and still not moving then the cable may be broken. Check that
Saturday, February 6th, 2010 AT 7:56 PM