Thread: Trolling motor interference

Here is the information i learned.

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Originally Posted by catchNreeleaze

Here is the information i learned.

Sent from my SM-N970U using Crappie.com mobile app

Reasons to NOT use Google AI as your primary source of education. Crazy some of the messed up "work" I've seen done on boats/cars. I used to say to myself "How did they think this was a good idea?"
Now I know why............


Seems the OP has disappeared so hopefully he has gotten his issues worked out.

Originally Posted by MDCrappie

Reasons to NOT use Google AI as your primary source of education. Crazy some of the messed up "work" I've seen done on boats/cars. I used to say to myself "How did they think this was a good idea?"
Now I know why............


Seems the OP has disappeared so hopefully he has gotten his issues worked out.

There i was thinking my screenshot proved you right and me wrong.

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Originally Posted by catchNreeleaze

Minn Kota comes with an internal ground. It is in the foot and is connected to the ground at the brush holder. Atleast it should be

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Minn Kota has not always put the internal ground in there motors
It’s according to how old his motor is as to when they started installing them from the factory
I’ve had the same problem he is having in the past and there was no internal ground in the motor
I took mine to a authorized dealer and they installed one and the interference went away

Originally Posted by catchNreeleaze

There i was thinking my screenshot proved you right and me wrong.

Sent from my SM-N970U using Crappie.com mobile app

Re-read the 2nd and 3rd sections in your screenshot. They pretty much directly contradict each other.

2nd - Always connect the battery cable to the engine block (or designated bonding point) to properly bond the electrical system. (1 says bonding is connecting all metal parts to equalize potential)

3rd - Directly connecting the battery negative to the hull can cause corrosion issues, especially on aluminum boats.

So 2nd says to connect the negative terminal to motor and connect that to the aluminum hull.

3rd says you shouldn't connect the negative terminal to the hull.

Originally Posted by MDCrappie

Re-read the 2nd and 3rd sections in your screenshot. They pretty much directly contradict each other.

2nd - Always connect the battery cable to the engine block (or designated bonding point) to properly bond the electrical system. (1 says bonding is connecting all metal parts to equalize potential)

3rd - Directly connecting the battery negative to the hull can cause corrosion issues, especially on aluminum boats.

So 2nd says to connect the negative terminal to motor and connect that to the aluminum hull.

3rd says you shouldn't connect the negative terminal to the hull.

The boat needs to be grounded through engine.

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IMO, issues in aluminum boats arise when the boat is used as a ground. Unless there is something I haven't seen, (and that is a distinct possibility) there is no way to install an outboard with electric start/charging system on an aluminum boat without having continuity between the battery negative and the boat hull. Again, IMO the key is not using the hull as a ground path to the battery.

My Fortrex had the internal ground with a fuse. The fuse never blew, and I never got rid of interference no matter where the wires were run or how many chokes were on the wires. How the noise from the 24v TM found its way to 12v system, I can only guess. My guess is that the trolling motor ground also had continuity to the hull and when the TM was running the 12v system picked up the noise. The brushless TM fixed it.

Originally Posted by justinp61

IMO, issues in aluminum boats arise when the boat is used as a ground. Unless there is something I haven't seen, (and that is a distinct possibility) there is no way to install an outboard with electric start/charging system on an aluminum boat without having continuity between the battery negative and the boat hull. Again, IMO the key is not using the hull as a ground path to the battery.

My Fortrex had the internal ground with a fuse. The fuse never blew, and I never got rid of interference no matter where the wires were run or how many chokes were on the wires. How the noise from the 24v TM found its way to 12v system, I can only guess. My guess is that the trolling motor ground also had continuity to the hull and when the TM was running the 12v system picked up the noise. The brushless TM fixed it.

This 100%. Never use the hull as the return path (ground) for accessories. The negative terminal is connected to the hull (bond not ground) and also to a "bus bar". You should have a ground wire for each accessory running to the bus bar.

My situation was the opposite. My older Minn Kota (24v) did not have an internal ground. When I used the TM it would cause a blacked out line on my lowrance. When I would let off the pedal it would go away. I ran a 16ga wire from my negative terminal on the starting battery to the negative terminal of the trolling motor. No more blacked out line when TM was used.