A/C only blowing cold when set to MAX

[8131full]

Took truck to dealer because AC was only blowing 77deg when ambient was 85deg. They said there was nothing wrong because when they set it to MAX AC, it blows super cold and works fine. When set to Auto though, back to 77deg. When using the remote start from the app and turn on climate control to cold - 77deg. They said I wasn't driving it long enough to get cold. But when I pushed the 'auto' button in front of mechanic and it blew 77, they said thats by design. Looking for any guidance for when I take it back to have them re-check it. Thanks.

 

[99WhiteC5Coupe]

Took truck to dealer because AC was only blowing 77deg when ambient was 85deg. They said there was nothing wrong because when they set it to MAX AC, it blows super cold and works fine. When set to Auto though, back to 77deg. When using the remote start from the app and turn on climate control to cold - 77deg. They said I wasn't driving it long enough to get cold. But when I pushed the 'auto' button in front of mechanic and it blew 77, they said thats by design. Looking for any guidance for when I take it back to have them re-check it. Thanks.

How long have you owned the vehicle? Did the a/c work differently in the past?

When the a/c is turned to MAX, it causes both radiator fans to run on high speed. When you set the control to AUTO and it runs at 77 degrees, do both radiator fans run - or only the left (driver) side fan? Any time the a/c is in operation, both radiator fans should run (but not necessarily on high speed).

 

[8131full]

How long have you owned the vehicle? Did the a/c work differently in the past?

When the a/c is turned to MAX, it causes both radiator fans to run on high speed. When you set the control to AUTO and it runs at 77 degrees, do both radiator fans run - or only the left (driver) side fan? Any time the a/c is in operation, both radiator fans should run (but not necessarily on high speed).

Thanks for that, going out to check the fans right now. I've had the truck since day 1, and it only started not working this year. About 3 weeks ago when I first used the AC this season. Prior to this year, the AC would blow cold via the Auto, and the temp could be adjusted that way.

 

[Gary Waugh]

Is it actually blowing at all? There is a resistor ladder that is used to set slow fan speeds and on max speed, the resistor is bypassed. The resistors often fail which means the fans only blow when on max.. can you see if the cooling system is blowing any air at all? If it only blows on max, then I would suspect the resistors have failed on the fan blowing motor.

 

[Trainmaster]

The newer ones at least have no resistors. Computer controlled. You never know what's going to happen when you start the car. Rear defogger? A/C? Who knows?