Trolling motor electrical interferace with depth finder

[a124ave]

I have a Minn kota Endure max with Digital Maximizer I believe model # is 1352155 causing interference with Hummingbird Matrix 10 Depth Finder. Both connected to same battery, What can I do to eliminate this except having to purchase another battery just for it.

 

[gm280]

You can buy, or make, a filter that goes on either the depth finder or trolling motor or even both units to filter out the PWM circuit frequencies that will travel on the DC line back across the battery to the depth finder. The sell RFI filters in various audio shops and that should fix your interference. That is unless you have the depth finder's transducer mounted to the trolling motor foot...

 

[a124ave]

Thanks gm280 I will look into finding them. No this on a 14' john boat. Transducer is mounted on boat and trolling motor is attached when used on other side of motor. It is definitely the trolling motor doing it because when testing by turn motor on and off screen goes from snowy to clear and normal.