tahoe air blows out of vent only

[tahoe99]

hi i put a new blend door actuator in now when i switch from vent to floor or defroster it stays on the dash vents i look at the actuator it looks like it is trying to move but some time it will moves it moves at easy by with out the actuator on it any ideas on this

---------- Post added at 06:13 PM ---------- Previous post was at 06:12 PM ----------

it a 99 tahoe