Heater on entire driver side including defrost not working
 

2004 Chevy LS Extended Cab - Entire Driver side including defrost & floorboard blows cold air only. The passenger side works fine. We've had the battery replaced & during the summer had the AC recharged as well. My mechanic said he would have to take the entire dash out??? Any idea what it could be & is it necessary to pull out the whole dash to fix?

Blend door
 

My jeep had this issue. It had a two part blend door. This door controls heat or cold control. One side of the two part door was broken.

Any further analysis on this issue?
 

My 2006 Silverado just started doing something similar. Air was working fine, but now the driver's side controls only blow very hot air, while the passenger side blows cold,

Today when I shut the truck off and turned it back on, I got the cold air to work on left and right controls initially, but after 3-4 minutes, the hot air on the drivers side starts blowing again. Passenger side is fine.

Thoughts or suggestions as to the cause or fix?

Found some youtube videos that show replacement of the AC actuators that control the AC/heat functions. Just do a YouTube search for replacing the actuators.

Actuators