front passenger blows warm air, driver and back seat vents blows hot air.
air conditioner blowing hot air on 2004 Chrysler Pacifica
Your A/C system may be low on charge allowing the front to work slightly and the rear to not work at all. Your best bet may be to have the A/C system checked by a qualified technician to confirm the low charge condition. If the system is low and no leak is noted at this time it would be a good idea to add some leak detection dye to the system when the recharge is done. Having the dye in the system may help find the leak when the system gets low again.
I also had this same problem - AC blowing hot air. Turned out to be the wrong anti-freeze to water mixture in the radiator. This caused the AC to freeze up and not blow cold air.