Interference problem

[feelay]

I have an Hb 788 on my bow. I have the Hb dual beam transducer mounted on my Terrova. Has worked great for over a year and a half. All of a sudden I have been getting interference when the Terrova is running. The sonar is completely useless with the trolling motor running now. Makes no sense to me as it has worked well for so long up til now. Any ideas where to look?

[Shellback]

Cut in the transducer wire somewhere? Or something happening in the motor itself, bad brushes? Do you have a ground wire from the T/M skeg to the ground on the trolling motor battery? If not try that for a start, might help if it's the motor itself.

[feelay]

Yeah, could be the brushes. Been squeeking on each prop rotation for the past year, kinda getting louder.