I have a 2010 Chevrolet GM Tahoe hybrid and my air conditioning blows warm when gasoline engine is running, when running on battery (auto stop) the ac blows cold.

I've pulled the 10A AC compressor fuse for 30 seconds, then ran the truck with all HVAC off for 60 seconds, then turned on ac, no change.

The truck has 140k miles and has no other issues, everything except the ac works as it should. I had no symptoms leading up to this.

Please share troubleshooting tips if you have them.

 

Try putting a rag or other protective cover on a pair of Vice Grips. Then clamp off the heater hose going to the firewall. Stopping the flow of hot water to heater core. It doesn't have to be real tight.


There may be a HVAC blend door or other valve issue that is keeping the hot coming.

 

The more that I read through these forums the more that I see a lot of oddball issues that can be caused by low voltage from the 12V battery under the hood. Not saying this AC problem is caused by the 12V but if anything is acting up at all the 12v battery probably should be tested first to eliminate it as the problem since it is so common.................. I can tell you that my 2015 Ford escape is on its 3rd battery. (they don't make them like they used to?)