Hyundai Repair: 2003 Elantra Air flow control, air flow control, face setting

Question
Heat/AC Air flow stuck on "face" setting, will not change to defrost or feet. Is this a mechanical system that I may be able to repair or an electro/mechanical or computer managed system that may have failed and needs replacing by the dealer? Thank you in advance.

Answer
This is an electro-mechanical system, but you may still be able to fix it (or figure out the problem) yourself.  

If you look up behind the dash on the driver's side, you'll find two actuators.  The bottom actuator controls the temperature, and the top actuator controls the mode (i.e. which registers dispense the air).

Check to see whether the mode actuator is properly attached to the lever on the heater box.  If so, remove it and check to see whether the lever moves freely to its maximum position in each direction.  

If this all checks okay, you probably have a problem with the actuator itself.  Although it's possible you could still have a wiring or control head issue, these problems are less likely to have occurred.