cold air blows in rear side vents fine, but none at all coming from front vents.
The blend door that diverts air from the front to back may be stuck or broken.
No air at all or is it blowing hot?
These vans have separate HVAC units for the front and rear, including separate blower motors.
The blend door actuator for the front HVAC may be defective.
Both systems use the same compressor, condensor, drier. Each system has it’s own evaporator and blower. so I agree with Tester.
It could also be a bad blower motor, resistor pack, and/or control module. We won’t know until the OP comes back with more information. @knunya, are you getting no air, warm air, or air to the wrong vents?
My response was based on the limited info that was provided, and the most common cause for the problem.
vents don’t blow cold air.
the compressor works for both back and front. if its getting cold air in the back it makes sense that the door is stuck closed for the front not allowing the cold air up there.
Again, is it no air or is the airflow adequate but not cold?