Air door actuator behind glove box is making loud tapping sound?

The part was not AC Delco but some cheap one from Amazon that costs only $13. Also, I could turn the door by pivot using my hand, so there is no obstruction in the movement of air door. I feel that once I installed the new one, it starts to move the pivot as soon as I plug in the connector even with engine off which is normal. But once the air door comes to its final position that it is driving towards, the motor is still kept energized by the power supply through that connector and forces it to move but there is no space left to move as the door has reached its final position. Now the plastic gears inside it starts slipping to cause noise and it happens for about a minute and then stops maybe because power supply is taken off by computer. After this I opened the new actuator to see the state of gears and found no damage meaning they were slipping without getting broken - maybe the plastic they are made of is bit more elastic than solid plastic. How does the computer know when to pull off the supply when it should upon reaching final position by door? I am talking about the actuator that controls air circulation - inside or outside air.

It was resolved after I bought another one from O'Reilly auto instead of Amazon.