Posted By: Bill Durham
Trolling motor interference with Bow Mount Finder - 07/16/17 07:09 PM
Guys,
There was a recent thread about this and it tweeked me to fix mine. I have a Hummninbird 759CI on the bow and a Motor Guide GW80 trolling motor. The power for my Finder comes from the first of the 2 batteries used for the trolling motor.. fed to the front of the boat by the 3rd big wire run for the twist lock connector mounted in the boat. The first battery provides the ground connection for the trolling motor so the finder gets ground from that battery as well. The interference happened everytime I turned on the trolling motor.. a big spike on the screen than a masking type of interference. I know that is the worst possible hookup for interference.. so its with great joy that I report that I fixed it!
The fix was adding shielding to my power cable. The power connection for the finder comes out of the back of the twist lock connector for the TM. My power cable for the finder is about 4' long. Its a 2 conductor unshielded cable provided by Humminbird and I was able to cover that cable with a tinned copper shield cable and terminate that shield to the ground connector in the twist lock. Like everybody else, I had cable tied the transducer cable to the TM power cable.. so I separated those cables as well. The interference is gone! I am a happy camper!
Braided wire shield cable can be bought at Mouser.com Its a pain in the butt to push the wire through the braid.. if you had to do something longer than the 4' I did..you will need some kind of messenger cable to push through the braid first and then pull the power cable back through.
Good luck
BD
There was a recent thread about this and it tweeked me to fix mine. I have a Hummninbird 759CI on the bow and a Motor Guide GW80 trolling motor. The power for my Finder comes from the first of the 2 batteries used for the trolling motor.. fed to the front of the boat by the 3rd big wire run for the twist lock connector mounted in the boat. The first battery provides the ground connection for the trolling motor so the finder gets ground from that battery as well. The interference happened everytime I turned on the trolling motor.. a big spike on the screen than a masking type of interference. I know that is the worst possible hookup for interference.. so its with great joy that I report that I fixed it!
The fix was adding shielding to my power cable. The power connection for the finder comes out of the back of the twist lock connector for the TM. My power cable for the finder is about 4' long. Its a 2 conductor unshielded cable provided by Humminbird and I was able to cover that cable with a tinned copper shield cable and terminate that shield to the ground connector in the twist lock. Like everybody else, I had cable tied the transducer cable to the TM power cable.. so I separated those cables as well. The interference is gone! I am a happy camper!
Braided wire shield cable can be bought at Mouser.com Its a pain in the butt to push the wire through the braid.. if you had to do something longer than the 4' I did..you will need some kind of messenger cable to push through the braid first and then pull the power cable back through.
Good luck
BD