I have a chevy venture. I need to know where the air vent accuator is located.

Under the dash. Likely in a difficult to reach location if its like most vehicles I've worked on.

The blend door actuator is located under the dash on the passenger's side.

Ok. FYI. There are two actuators on a chevy venture. One on the passenger side and one on the drivers side under the dash. The passenger side controls the vent to floor to defrost. The drivers side one controls the in between vent/floor, and floor/defrost.