I've got an 04 Silverado 1500. The heat is stuck on the driver side and wont change from heat no matter what I do. I turn the a/c on and still stays hot. The passenger side operates like its suppose to. What do I need to replace in order to fix it. Thanks

 

so you wanted a made in china electronic door instead of a manual lever. look where you are now ! ?

you could blow money replacing the mixing door motor. but it would be better if you found a panel to peek in and see what the issue is. you could have a door sticking, have a dead door hinge motor, or dead control pot (the thing you turn) (broken and never sending the signal to open/close the mixer door)

another way would be to remove that one control motor and give it power (due to "design improvements" it might be too complicated, forcing you to guess if you don't have a dealer tool)

definitely up in the air at this point!