Mounting Transducers to Trolling Motors

Most anglers that use an electric trolling motor, and use it often, have some sort of depth finder mounted on the boat as well.Often, it is desirable to have the transducer mounted on the trolling motor, but this can be a difficult task.It is important that the transducer and the routing of the cable does not interfere with the trolling motors operation.You must route the cable so that it does not get pulled, cut or crushed.On certain model trolling motors, especially bow mounts,this can be a challenge.

First, you should have the right type of transducer for mounting to an electric trolling motors lower unit.This would, most likely, be a Puck style transducer.Other style transducers will work, but only the Puck is designed for this application.With this style, the only hardware you need is a heavy plastic cable tie or a metal hose clamp to strap the transducer onto the motor.The Puck has a curved top to fit the round shape of the motors lower unit and slots in it to accept the strap.

We recommend the cable tie over the hose clamp because it has proven to be more forgiving when the motor crashes into an underwater object.Instead of breaking the transducer, the cable tie allows it to “slip” out of the way.Puck transducers come in different sizes, depending on the cone angle of the transducer, but they are all meant for the trolling motor. For your most accurate readings the transducer should be pointing straight down.

Some anglers like to position it so that they are shooting in front of the boat so that they can see what’s up ahead.This sounds good in theory, but in reality, you are creating a large amount of Dead Zone which will make anything near the bottom virtually invisible.Don’t worry about being perfectly level, though.The wave action makes that almost impossible.Just get it as close as you can. You can, however, side scan with a puck transducer. This works on any depth finder, although you need to interpret what you see.Simply rotate the transducer on the motors lower unit so that it is pointing just down from horizontal.Set the depth finder to it’s maximum range and steer the motor around. This works better in deeper water.Ideally you don’t want to see bottom or the surface at all. Again, dead zone will make anything near the bottom invisible. Narrow beam transducers work best for side scanning.

With the Puck transducer mounted, you now need to route the cable up the motor shaft, down the motor bracket, and to the back of the depth finder.Foot control trolling motors provide the most challenge when routing the cable.All of the motors movements make it hard to keep the cable from being pulled, crushed, or cut.Refer to the images here to help in the routing of your cable.

With electric trolling motors getting more powerful and complicated all the time we are seeing more and more interference on the displays of our depth finders.In the past, interference has mostly been due to noise in the power lines of the boat.This can usually be solved with fairly simple grounding.Now, we are seeing interference that is being radiated directly from the motor shell into the transducer.This can more difficult to solve.You can identify the type of interference by simply unplugging the transducer.If the interference disappears, you have a radiation problem.If not, you have a power line problem.Check out this tip for more information about interference.