It is possible that the door has broken/separated from the servo. That would allow you to move the servo gears without changing the angle of the door. When you moved the gears to their limits, was the limit caused by the gears ending or by the related door contacting an interior stop? Can you see the attachment to the blend door moving?

 

Thank you for replying
It feels like the doors are hitting the actual stops when turned by hand . Each door driven gear rotates about 300 degrees and feels like it is connected to a blend door or something . Is there two separate compartments, passenger and driver, with individual blend doors controlling each ? I cannot see inside the box to see if the doors are actually moving but feel ok . I noticed the driver side of the evaporator core holder box, or what ever the technical name for it is , is cool to the touch compared to the passenger side which feels warm .

 

Which blend door actuator are you talking about?

 

Driver side and passenger side , They do not seem to be connected and rotate independently of each other ,depending on the temp setting selected by the passenger or driver . This is one of those systems where the passenger and driver can select totally different temperatures at the same time .

 

With dual zone controls, there are separate blend doors for the driver and passenger sides. Given that the lines and evaporator indicate cooling is occurring, it seems like the doors aren't moving. When you switch between AC and heat, can you hear the servo motors moving. I wonder if there is a wiring or computer issue that is preventing the command from getting to the doors.

 

I was thinking the same thing , but after removing the servos I can turn the door levers by hand and they seem to have resistance consistent to damper door movement . But I can't tell for sure . I'm going to buy one of those handheld borescopes/inspection cameras . Maybe if I remove the grommet for the evaporator sensor ,there is enough room to insert the camera and see what if anything is actually moving ?