A/C blowing hot air

2018 GMC SIERRA
68,000 MILES • 5.3L • V8 • 4WD • AUTOMATIC
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EVAP drips condensation, compressor engages, 1234 refrigerant showing charged, engine fan blows, all fuses good. Next steps?
Aug 25, 2021 at 10:36 AM
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JACOBANDNICKOLAS
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Hi,

It sounds like the A/C is working. What I suspect is the blend air door isn't working properly. The blend door is what is responsible for the air temperature entering the vehicle. I would suggest removing it and seeing if it responds when the temperature is changed from hot to cold and back again. If you find it is bad, here is a link that shows in general how one is replaced:

https://www.2carpros.com/articles/replace-blend-door-motor

On your vehicle, it is referred to as a temperature valve actuator. Now, there is a difference between automatic climate control and manual climate control. I am going to provide the directions below for replacing the actuator for a manual system. If you have an automatic system, let me know.

The last pic is the recalibration procedure.

Let me know if this helps or if you have other questions.

Take care,

Joe

See pics below.


Aug 25, 2021 at 8:32 PM
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Thanks for the info. The gauge that came with the r1234 showed green but I gambled and added some refrigerant anyways. That did the job and it's blowing cold now. Hopefully it's a very slow leak.
Aug 26, 2021 at 4:07 AM
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JACOBANDNICKOLAS
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Hi,

Excellent! I'm glad to hear you got it working. I know where I am, we really have needed it the past few days. LOL

Take care and please feel free to come back anytime in the future. You're always welcome here.

Joe
Aug 26, 2021 at 8:12 PM