Heater stuck on, on 2005 gmc sierra

[GR8TSCT]

Hi, my name is Scott and i just purchased a used 2005 GMC Sierra. just like all used vehicles it needs a few things repaired. I am currently working on my A/C and heater controls. The heater is stuck on, no matter what possition the temperature is set at. I know there are a number of things to look at, but i thought if anyone has run into this problem and if there was a part that was prone to braking within this system so i may start there. the A/C compressor seems to run just fine, just the door between the heater core and the evaporator is stuck on heat. If anyone has any ideas i would greatly appreciate it. Thank you!

I am really happy with this truck and i am happy to have my first GMC truck.

 

[GR8TSCT]

So I did my research and found out the most common thing that goes bad is the temperature control door actuator. It is actually easy to get to, and inexpensive to give it a try. Here is a video of how to replace it: https://www.youtube.com/watch?v=_Suo7gNvLTM

I hope this helps those that have the same problem. If anyone has any other information that would still be helpful.

 

[GR8TSCT]

I will let me know what it is when I get into working on the truck this week what it actually is. Thanks