I bought a new ff a few weeks ago it is mounted on a 8' Livingston I put the transducer on a board that clamps on the back of the boat. Had to tweak it a few times to get it in clean water but I have it reading good now. But the problem is I still get a lot of interference when I turn the the sensitivity up more then 60% I am getting a good bottom read but screen goes almost black when I try to turn it up. For the power supply my battery box has 12 volt accessory outlets like a cigarette lighter outlet I wired on a plug so I can remove easily. Could I be getting interference from running off the same power supply as the motor.