Ac compressor doesn't stay engaged on 2010 Dodge Ram 2500

Whether the truck is idling, driving, or just starting. 90% of the time it blows hot air. Dealer says freon is fine and they replaced valve. Any suggestions?

Asked by for the 2010 Dodge Ram 2500
what valve did they replace? is the cooling fan coming on when you turn the a/c on
Fan Is coming on. They replaced expansion valve.
is the low side tube cold when a/c is running if so then you could have a blend door problem if its not then you will have to hook up a gauge set to check the pressures this should be done by qualified personnel