I have a 998c HD and 360 on bow as well as a 998c HD at the steering helm. I get interference on 360 when both units are on. I have tried powering both units with the 360 on, but unplugged the transducer to the 2nd unit at the steering helm and the interference goes away. Any suggestions to remedy this? both units already run off of separate batteries but the power wire for the 360 bow unit does run up the same wiring cavity as the other unit.