A/C takes 3-5 minutes to start cooling dealer says nothing wrong

Whaler27 · Jul 30, 2024

pinebaron said:
Not sure whats wrong with yours but my AC starts cooling instantly and so does seat ventilation, its fan is clearly audiable when on.

The next closest GMC dealer is about 70 miles away. Someday, when I have nothing better to do, I’ll have to take the truck there, I guess.

On the good news front, the parking sensor my dealership broke during their two day winch installation, and failed to repair during their all-day repair appointment, has arrived after only waiting a month, so they’re now prepared to remove the bumper to replace the sensor they broke (but didn’t mention breaking). I’m hoping the third time/effort will be the charm…

bookemdanno · Jul 30, 2024

So I got in the truck today & noticed that my A/C was little warmer than it has been and made me think of this post. I do keep it on auto, but noticed that the recirculate button was turned off. Once I pushed that back on I had a ton of cold air. Just something to check if you haven't already.

RebelDS · Jul 31, 2024

Based on this thread, I left my truck sitting in the sun instead of under a roof and it was sweltering. I got in it and cranked it up and it cooled off pretty fast. Apparently, I’ve been fortunate that mine works great and I hope it continues

Jorayr97 · Jul 31, 2024

bookemdanno said:
So I got in the truck today & noticed that my A/C was little warmer than it has been and made me think of this post. I do keep it on auto, but noticed that the recirculate button was turned off. Once I pushed that back on I had a ton of cold air. Just something to check if you haven't already.

On my 2020 when the system is set to auto the recirculate is turned off. If I turn recirculate on, the auto feature turns off.

Dug · Jul 21, 2025

Hello all, new guy here. Has anyone gotten any new insights in this issue. I've got a 2023 at4 2500 and this ac issue really starting to get on my nerves. Just exactly like to OP describes, it takes a bizarrely long time for the ac to start blowing cold air. Particularly after the truck has sat for a day or so. Doesn't do it so much if I've just been driving and have gotten back in the truck. Once it decides to blow cold it does a great job cooling the cab. And it's not like it gradually starts to blow cold. It hot air for several minutes sometimes and then boom! Nice cool air. Could this be a pressure switch issue?

gemarsh · Jul 21, 2025

Dug said:
Hello all, new guy here. Has anyone gotten any new insights in this issue. I've got a 2023 at4 2500 and this ac issue really starting to get on my nerves. Just exactly like to OP describes, it takes a bizarrely long time for the ac to start blowing cold air. Particularly after the truck has sat for a day or so. Doesn't do it so much if I've just been driving and have gotten back in the truck. Once it decides to blow cold it does a great job cooling the cab. And it's not like it gradually starts to blow cold. It hot air for several minutes sometimes and then boom! Nice cool air. Could this be a pressure switch issue?

Welcome.