If you replaced the blend door actuator it may have a relearn procedure. Check the hoses going into the heater core to be sure they are both hot after the car has reached running temp. This will let you know if you have a bloked heater core.
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Perform the self test on the EATC system first. To do this, press the OFF and FLOOR buttons at the same time, then release them. Then right away press and release the AUTOMATIC button. The screen should show a few dashes indicating it entered the self test. At the end of the test, look for a code 024 or a 025 for faults with the temperature blend door actuator. If a code 024 is retrieved, the problem is a hard fault. To exit the test and clear codes, press and release the front Defrost button.
If a code 024 is present, remove the blend door actuator from the heater case (it is located behind the radio area). Re-run the self test and monitor the blend door actuator to see if it moves. If it now moves and the code is no longer present, check for a binding temperature blend door. Refer to TSB 02-23-6 for information on repairing a possible secondary blend door problem.
If the blend door actuator still does not move with it removed physically from the heater case, put a Digital Volt-Ohm Meter (DVOM) between the Orange (OG) and Dark Blue/Light Green (DB/LG) wires at the actuator. Monitor the voltage while performing the self test. Close to battery voltage should be present indicating the module trying to operate the blend door actuator in one direction, then the polarity of the voltage should reverse and the actuator should go in the opposite direction. If there is voltage present but the blend door actuator does not move, replace the blend door actuator.