By October 22, 2012 0 Comments Read More →

AC Blowing Hot Air

I am hoping you can post an answer to this weird situation…

My Chevy Avalanche (with the fancy dual climate control digital display) blows 140 degree air out of the vents whether I have it set at 60 or 90 or anywhere between and also whether I have the air conditioner compressor on or off.

Obviously something has triggered it to blow full heat. I can’t find any relays or fuses that seem to control it. I don’t see any obvious problems like broken wires.

I bypassed the heater core by removing the heater hoses and looping them back to the water pump and that makes the air come out at a normal temperature, but obviously this is a bad short term solution, especially with cooler weather approaching.

As a side note.. how in the heck do you remove the heater hoses that are secured by a plastic ring? I was only able to remove those secured by a good old fashioned metal clamp.

thank you


Howdy Gary,

Your situation is a little trickier than most… are going to need a scan tool and read the computer codes to see if there is any trouble codes stored in memory…I bet there is.

I did call ask one of my AC techs to do a little research for you and see if there is anything you can do yourself. He suggests that you try this recalibration procedure and see what happens.

1. Engine OFF
2. Remove HVAC/ECAS fuse (probably located under the hood) for 15 seconds
3. Reinstall fuse
4. Start engine
5. DO NOT do ANYTHING for 60 seconds

Make sure the fuse is not blown first of course before you just remove it. If this does not help you, you will need to see a mechanic with a scan tool and one that is experienced with new model AC systems like this.

The heater hose removal part, they make a special tool that will release that plastic clamp from the hose. You might be able to buy this tool at your local auto parts store…..or the GM dealership.

Keep me posted as to what you find out will ya?

Austin Davis


Reader Follow up

I re-hooked up the heater core today and for some reason it is properly blending. So maybe pulling the fuses did reset something and fix it. Who knows? For now I’ll cross my fingers that it will stay fixed. It is not pleasant to have 140 degree air blowing out of the dash in Texas, even in winter!

take care

Posted in: A/C and Heater

About the Author:

Austin Davis, consumer car repair advocate. "Hi there! I love to help people solve their car repair problems and I hope my site was helpful to you today. Thank you for stopping by."