CHEVROLET EQUINOX DEFROSTER NOT WORKING

When I Turn My Defroster On Air Does Not Come Out The Driver Side Defrost Vent Causing The Windshield To Fog Up And Not Clear.

Defrost Will Not Work. Is It A Mode Door Actuator? How Difficult Is This To Get To And Could It Be A Diy?

The Fan Blows Air Cannot Control The Flow Of Air When Selecting Floor Dash Vents Or Defrost. No Flow Is Changed, It Seems To Be In Defrost...