My Blazer is blowing hot air at all times. Have fully charged AC system but cant get the air to blow cold. Wondering if it is the interior climate sensor. When I turn the key forward, I can hear a low growling noise coming from the sensor above the drivers left shoulder. Can this be sensor replaced? If so, how do I get at it under the headliner without tearing sh*t up?

 

Most often this is a problem with the blend door actuator which selects whether hot or cold air comes out the vents. If you check the metal A/C lines under the hood and they're cold and sweaty then that's your problem. Do a quick search on blend+door and you'll find tons of messages about it and a few how to fix it links. It's a very common problem with the Blazers.

 

Thanks for your input. I thought it was blend door related, but figured that the interior sensor might be the root cause. I dont think it should sound like it does.