04 pacifica heat
 

im having a problem with changing from floor to vent & vice versa. i can change it to the floor & it blows out the defroster & very little on the floor. is there a way to reprogram the unit. i have the digital unit.

i dont exactly have much knowledge on digital climate control but if the valves still operate on vacuum then check the vacuum lines

The blend air actuators are DC servo motors, not vacuum motors.
If airflow is an issue, check/replace the cabin air filter.
The two blend air actuators (one for the front, one for the rear) are indentical components. If airflow is OK, and the problem is airflow direction you could swap the actuators. If the problem moves with the actuator, you've found the problem.