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Automate Your Trim Tabs - Photo 3

The control unit contains fore-and-aft and port-and-starboard angle-sensing accelerometers and must be mounted flat. The system compensates if a given horizontal surface (the deck inside the helm console, for example) isn’t quite level with the water. The arrow on the control unit must also point forward, parallel with the boat’s keel.

Automate Your Trim Tabs - Photo 3The orange and black power wires connect to DC power (A), with a catch. The power wire has to be energized with the ignition key on, but dead with the key off. This is more complicated than it sounds. Ask your mechanic or engine manufacturer which is your ignition key accessory wire so you avoid cutting the wrong wire(s). Double-check with a multimeter before cutting.

The cable from the auto tab control panel simply plugs in (B). An additional panel for a second helm station can be plugged in here as well (C), although foregoing a second keyboard does not obviate manual trim-tab control at a rocker-switch-equipped second station.

If there is a tricky part to this installation, here it is. For starters, Bennett’s original multicolor wire harness extended directly from the original rocker switch at the helm all the way back to the HPU. We cut this multicolor harness between the helm station and the relay module, and butt-spliced in an array of plugs that Bennett supplies. These new plugs then went into the control unit (D) so that we ultimately had one multicolored harness running from the new helm rocker directly to the control unit and another multicolored harness exiting the control unit and going to the relay module back near the HPU.