Trolling motor interference

[Dutch552]

Yesterday on the lake about halway through the day I suddenly developed bad electrical interference on my Huminbird bow unit attached to the trolling motor. I swapped head units but the interference remained each time the trolling motor was activated. It shows up as a blacked out portion of the water column from about 10 feet down to the bottom of the screen and returns to normal after the trolling motor is stopped. Since I haven't changed anything on my rig and it was working fine earlier in the day, any ideas where to start looking for causes or solutions?

Humminbird 727 with newer Motorguide 70lb 24v TM

[Dutch552]

Any ideas?

[crappiedoc]

Are they on the same battery? If so, hook them up to different batteries. If they are on different sources, sometimes a piece of rubber between the clamp /transducer and the motor will help ground out interference. A piece of inner-tube works well. Also, check your cords for damage, pinching.

[Dutch552]

They are on different batteries. I will cut a piece of rubber tonight and put it between the foot and the transducer. Thanks for a place to start.

[Barnacle Bill]

Dutch, go to section 9 here http://tnhatlfs01.thenethouse.com/st...r%20Manual.pdf and see if this helps. It's from Minnkota but the solutions for interference would apply to you too.

[Humminbird_Greg]

Dutch,
Sorry for not seeing your post sooner but I have been tied up at work and have not had the time to look at Crappie.com.

You need to call the Humminbird Customer Resource folks as well: 1-800-633-1468 and try some of the suggestions that they have for you. From your description of it working fine that suddenly having the interference I would guess that a grounding wire has come loose somewhere.