Front AC blows warm and not the usual suspect

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circusdevil

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First I have an 05 denali. The back AC works perfectly. The front started to get warm and will only cool some what when driving. I checked the blend door actuators by watching them move and taking them off and turning the door manually and the AC didnt get cold. I did even the top one behind the passenger air bag. It did get hot when i turned them but just warm when manually turning them the other way. This leads me to think it has to do with something not electronic. The rear blows very cold. The front cools a bit while driving but not much. I cant find a diagram of the lines from the compressor. Is there a line to just the front that the refrigerant is not getting to? Im stumped. Any help or suggestions would be completely appreciated. Thanks
 

PNWYukon

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You could try this, unless you have DTC's?

RE-CALIBRATING ACTUATORS

When replacing the HVAC control module it will be necessary to allow the HVAC control module to perform a calibration process. When installing the HVAC control module be sure to perform the following:

IMPORTANT: Do not adjust any controls on the HVAC control module while the HVAC control module is self-calibrating. If interrupted, improper HVAC performance will result.


  1. Place the ignition switch to the OFF position.
  2. Disconnect the scan tool.
  3. Install the HVAC control module.
  4. Connect all previously disconnected components.
  5. Start the vehicle.
  6. Wait 40 seconds for the HVAC control module to self-calibrate.
  7. Verify that no DTCs have set as current DTCs.
When replacing the HVAC actuator it will be necessary to allow the HVAC control module to perform a calibration process. When installing the HVAC actuator be sure to perform one of the following:

IMPORTANT: Do not adjust any controls on the HVAC control module while the HVAC control module is self-calibrating. If interrupted, improper HVAC performance will result.

Preferred Method (w/ Scan Tool)

  1. Clear all DTCs.
  2. Place the ignition switch in the OFF position.
  3. Install the HVAC actuator.
  4. Connect all previously disconnected components.
  5. Start the vehicle.
  6. With the scan tool, initiate the Motor Re-calibration feature of the Heating and Air Conditioning Special Functions menu.
  7. Verify that no DTCs have set as current DTCs.
IMPORTANT: Do not adjust any controls on the HVAC control module while the HVAC control module is self-calibrating. If interrupted, improper HVAC performance will result.

Alternate Method (w/o Scan Tool)

  1. Clear all DTCs.
  2. Place the ignition switch to the OFF position.
  3. Install the HVAC actuator.
  4. Connect all previously disconnected components.
  5. Remove the HVAC/ECAS fuse for a minimum of 10 seconds.
  6. Install the HVAC/ECAS fuse.
  7. Start the vehicle.
  8. Wait 40 seconds for the HVAC control module to self-calibrate.
  9. Verify that no DTCs have set as current DTCs.
 

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