I can't plug in the connector

Sometimes the connectors can be tight to push in. You can confirm the connector is properly seated and connected when you hear a  click sound and you cannot pull it out with pinching the release mechanism. It should not come out by pulling on the connector (please do not pull on the wires).

Check it is clean

If it is difficult to plug in, check that there is no dirt or debris around the mating side and on the seals that is preventing it from connecting.

Also please make sure the connector and actuator are clean and dry. Dirt and moisture on and inside the connector or actuator can cause problems in the future.

Locking tab

Make sure that the locking tab is not pushed in until the connector is fully pushed it, as it'll prevent the connector from being plugged in.

Bracket

You can also try pushing the bracket on further as it could be just ever so slightly protruding and making it harder to push the connector on all the way.

Check the pins

However unlikely, you can also inspect the connector pins to make sure they have not been bent.

Any damages during installation are not covered by warranty so please take your time and be careful. It is recommended to consult a professional if you have troubles.