no A/C at idle

Newbe here I hope this is not a beat to death thread. I have a 01, 2500HD, 8.1l, AL trans. At idle or in bumper to bumper traffic, I have no A/C just blows warm. It has done this since day one, and I took it to the stealership, and they said it was normal, in order not to over heat the Allison trans. This is driving me nuts. we now live in NC and it is no longer tolerable. Does anyone have any ideas? Thanks for your help!

Newbe here I hope this is not a beat to death thread. I have a 01, 2500HD, 8.1l, AL trans. At idle or in bumper to bumper traffic, I have no A/C just blows warm. It has done this since day one, and I took it to the stealership, and they said it was normal, in order not to over heat the Allison trans. This is driving me nuts. we now live in NC and it is no longer tolerable. Does anyone have any ideas? Thanks for your help!

If you have too much refrigerent/excessive high side pressures , in the system, the ac compressor will be commanded OFF...

If the engine is overtemping the a/c is commanded OFF..

what is the condition of you coolant ///system///thermostat///coolant cap///pressure test coolant system///fan clutch n/g etc.......

coolant and everything good, truck has been doing this since day one.

Newbe here I hope this is not a beat to death thread. I have a 01, 2500HD, 8.1l, AL trans. At idle or in bumper to bumper traffic, I have no A/C just blows warm. It has done this since day one, and I took it to the stealership, and they said it was normal, in order not to over heat the Allison trans. This is driving me nuts. we now live in NC and it is no longer tolerable. Does anyone have any ideas? Thanks for your help!


Proper amount of R-134a ?

Post back low and high side AC pressure at idle and at 2K rpm.

coolant and everything good, truck has been doing this since day one.

it is possible the ac low side pressure switch is defective...this switch should cut out ac compressor around 5 psi...

this switch is used to protect compressor from lack of refrigerent,,,which if it did occur would damage it...

you should have a ac repair shop check out the low/high pressures to see if it is specific to ac or the engine pcm...computer....

what is the idle speed? if it is too low the pcm will not allow
the compressor to come on no matter what you jump.
have seen many of the 5.3L & 6.0L trucks do this due to throttle
body coking.

Back to the stealer I went to have checked out, everything ok, says them. Told that that's the way the A/C works on the 8.1 with the Allison. I just can not believe it though, NO A/C IN BUMPER TO BUMPER CRAWL! No wonder GM is in the shape it's in.

Back to the stealer I went to have checked out, everything ok, says them. Told that that's the way the A/C works on the 8.1 with the Allison. I just can not believe it though, NO A/C IN BUMPER TO BUMPER CRAWL! No wonder GM is in the shape it's in.

GO TO a a/c repair shop that can find this problem...this is something that a good reputable a/c repair shop should fix quickly...

Have you checked your fan clutch? may be not pulling enough air across condenser...