I have an 02 Dakota with a heater problem. I can not get the air to blow out the floor vents only when set to heat on the floor. It comes out the dash vents also. I am thinking possibly an actuator issue but can not figure out which one. Any help with this would be appreciated. I figure someone here has had the same issue.

The actuators are electric in your '02. It would be the floor/defrost actuator.

If the calibration is out you need a dealer to reprogram it - using their DRB III.

What would cause calibration to be off? Supposing that is the problem? Also can the dealer test to see what the problem is?

It might have just failed.

Yes a dealer can check it with their DRBIII, and cycle all the actuators.