chamberlain motorlift 1000 unplugged wire

Hi.
I recently bought a house with a garage and it has a chamberlain motorlift 1000 which works except that it always goes all the way to the ends when opening and closing. Adjusting the open and and close screws seems to do nothing so I opened the motor housing and I noticed one of three wires is not plugged to anything. It seems that the variable resistors that are supposed to be setting the threshold for how much it openes and closes is not giving any signal to the computer controlling the motor so it always goes all the way in both directions. I have searched for a place where the third wire should be connected but can't seem to find it.
Here is a picture of the wire that is unplugged: https://ibb.co/0MZRwKH
Can anyone help me figure out where it is supposed to be connected?
Thanks.

I opened the motor housing and I noticed one of three wires is not plugged to anything. It seems that the variable resistors that are supposed to be setting the threshold for how much it openes and closes download video instagram story is not giving any signal to the computer controlling the motor so it always goes all the way in both directions.

Turns out that the there was a missing piece in the setup. There is supposed to be a third white plastic piece in the middle that connects to the motor and moves a contact up and down to touch the contacts on the other two white pieces. I found a local supplier that had this whole unit and I just changed it so now it works. Cost about 40 us dollars. If I had ordered it online it would probably have cost something similar since I live on an island and the import fees are high.