We have a dual air system where the back passangers can control thier own climate.
What to do when you get heat in the front vents but no heat in the back vents? on 2005 Dodge Grand Caravan
Your vehicle has two separate HVAC units, one located in the front of the vehicle and the other in the rear. Both are controlled by a common control panel on the center of your instrument panel and an independent control for the rear passengers. You will have to have you Heating and A/C (HVAC) unit inspected. This can be diagnosed at you local dealership with their Scan tool.