Humminbird/minn Kota interference

I'm running an 899 on the bow with a min Kota maxim 74. I have it linked to my console unit and use the transducer off of the transom. Both units are direct wired to starting battery with wires on right side of boat. The trolling motor wires run the left. Every time that I hit the trolling motor, I get interference on the ff, losing the depth and just filling the screen with trash. Is there a filter that I can add to help clear this?

Yes, it is called a choke. I actually have two on my front graph. One going from my plug in to my trolling motor and the other is a HB factory choke.

Mine does the same thing. Where can you buy one?

Thanks. $65??? Why is everything so expensive from HB? I've never had the issue before and plan on upgrading the tm soon so I guess I'll live with it for awhile and see what the new tm does.

I'm really starting to dislike my HBs and am seriously thinking of dumping them and going to Lowrance or Garmin. I'm working off of one transducer because the other stopped working and 2d barely works on this one ( only get dots, no arcs) and the temp stopped reading correct temps months ago. I don't really even trust it marking fish anymore

Looks like HB sells them. $65 TMC-1

On the Humminbird website there are a couple of suggestions for interference from Minn Kota TMs. One is a mod to the TM, one is tying the ground side of the trolling batteries to the ground side of the crank battery using a fused link. I'm having interference from my Motor Guide TM, going to try the battery connections first. My bow mount 858c is getting interference and I'm running it off of one of the TM batteries.
"Choke" is the generic name of an inductor. This is a passive electronic device that has a really high impedance or rejection characteristic for frequencies above DC. Basically, its a coil of wire usually wrapped around a core material. The wire has to be able to carry the current draw of the depth finder.. which is pretty small really. They are effective if the interference is being transmitted to your DF via the power connection.

I had same problem with my fortrex. Talked to a rep and it was a 3 amp fuse on the ground wire that was blown. Take off the cover of your trolling motor head and look for a blown fuse.

Ok will look. I just had it off recently but don't remember seeing a fuse. I did see two wires with male connectors but nothing for them to connect to which was odd

I heard that a ferrite ring will help with interference and only cost a few dollars. You might try that route first before dropping $65.

Just make sure you test while boat is in the water. I have been through this before

Call HB customer service, I had the same issue and they sent me one for free.

I had the same problem with my MK 101, they(MK) sent me a ferrit ring that didn't work.I ended up changing my transducer and now no problems !