Bennett Trim Tabs operate the reverse of what you might think. The port trim tab lowers the starboard bow. Conversely, the starboard trim tab lowers the port bow. The control is wired so that all you have to do is press the control in the direction you want the bow to move. The proper use of Bennett Trim Tabs becomes second nature after a short time....
This is straight from the bennett's site.
when you press the right bow down button the left tab will go down that is how it should work..