Interference can be caused by many things such as cable routing, worn brushes and water intrusion from the trolling motor, on board battery chargers. The ferrites are just one remedy that can work for some and not others. Its a process of elimination. One of the most common solutions is to separate the trolling motor power cables away from the transducer cable if possible
They are not together.. trolling motor wires are on the right side from center console and transducer wire ( 30 ft ) is on the left .. now , they are close right in the center where they com into the console.. I cant help that.. when I say interference, better description is it fades .. like I lose some of the signal.. not like lines straight up and down interference, if that makes any sense .. and when I am on the anchor feature..