AC doesn't work while idling Peterbilt 579

is your engine fan running while the a/c is on?

 

you got a fan over ride switch?

if so, turn it on, and see if that improves the a/c out put.

 

for only a 2 year old truck, it could be low on freon, but the radiator need lots of air going thru it with the a/c on.

 

Yep, sounds like a leak. With the engine running and the A/C on, watch your compressor clutch. If the compressor cycles off more than it cycles on, then it's likely that you've got a leak that has allowed most of the refrigerant to escape.

 

You may want so stick with Pete on that one. The HVAC on that model is computer controlled with faults read through ESA. There are 5 actuators in the dash which are prone to failure and control everything from the duct temp to air flow. Does the blower ever shut off randomly? ,or is it just blowing warm?

Worth a shot to at least check the refrigerant charge and for dye leaks. If its low it has a leak somewhere. Check the filter too. Easy access RH side under the hood on the cowl. Slide open door. They plug up real fast in dusty environments.