I know this is going to sound stupid, but I have to ask because I'm getting a lot of interference from the 2017 Ultrex and the new Garmin 106sv transducer. I mounted the TD to the bottom of the ultrex. There is a lot of EMI when I step on the pedal to move. I've tried a lot of tricks, but nothing is working.

Dumb question: I have the universal built in transducer on the Ultrex. If that cable is not plugged in to a control unit (106sv), is the Ultrex transducer still sending a signal into the water that is interfering with the Garmin?

I would first think that (with the current running thru the trolling motor shaft to power the prop and the t-motor cable from from ducer you are "using" zip tied or taped to it) the interference is happening like you said when the pedal is pressed. If you can move the cable for the ducer you are using away from the shaft and then press the pedal you'll know. Might have to buy those spacer kits that keep your ducer cable slightly away from the t-motor shaft and prevents the interference.

I moved my Humminbird for the helm to the trolling motor. Every time I stepped on the hot foot, the screen went completely bonkers. The Lowrance I had on the TM previously worked fine, it was just too small. I tried everything I could to fix the interference wreaking havoc on the Humminbird but nothing worked. Bought a new 9" Lowrance Splitshot and it works fine.

CF
I have my Garmin TD mounted the same way on my ultrex and have never had issue with interference. Not sure what the heck is going on.

Check the fuse in the head, sometimes if it’s blown, you’ll get more interference.

Couple of questions,. Are you powering the garmin from one of the 12v batteries that is being used for the ultrex? If you are using the same power source, try a seperate battery that is not used for the trolling motor. If the universal transducer that is built into the ultrex isnt plugged into a depth finder it will not send out anything. Note: I ended up adding a fourth battery to my boat specifically for the depth finder/360. Doing a current calculation on what i have running, would have dropping my starting battery to an unsafe voltage level by the end of the day. Did the transducer for the garmin come with any ferrite chokes? Might try this, as it can cause feedback on the cable. Lastly, try coiling the end of the transducer cable for the garmin up with as many tight coils as you can before it plugs into the depth finder. This is called an ugly balun, which can help with common mode (refl power, or emi). You can google ugly balun, but you dont need the pvc. Just coil it up and zip tie into a dunut, and see if it helps. And you can do this at home. Lastly which would be the hardest item to do, would be to add a ground wire down to the housing of the motor on the ultrex.. which I would do as a last alternative. Might call garmin, they should have a fix if all else fails. Curious about the battery arrangement.

Having your transducer cable run too close to you trolling motor power wires will also cause interference, try routing the transducer cable with several inches clearance from trolling motor wiring.

I had the same problem with a previous Lowrance unit and my trolling motor and I added a ground wire to the motor housing and that helped. I also wrapped the transducer cord several times around a ferrite ring and that seemed to help as well.

No.

Does Garmin come with choke filter for the power cord? That fixed most of my interference issues with my 'bird. The other thing I had to do was not attach my ducer cable to the TM at all.. I know I run a risk of hooking it on a stump or something, but with my XI5 there really isn't a way to attach it to the shaft. If Garmin doesn't offer that choke filter I'm sure the one for the 'bird would work also.

BD