Interference on my FishFinder... Any Suggestions?

[MustHuntAndFish]

Well... While most of the boats at the MID on Saturday were slaying, I had a slow day, mostly fighting with my newly installed PiranhaMAX 160.:Embarrassed:

I installed it myself so I knew there could be some glitches. When I launched and turned the unit on it read the depth just fine at the dock so I was very happy.:LOL: But as soon as I started the engine the unit thought that there were fish everywhere.

Whenever the motor is shut off it gets true readings but when turned on there is intereference and it thinks that the lake is one big school of fish.:Confused: I mounted the transducer 16" away from the motor... instructions say 15" minimum. The only other idea I have is the transducer wiring is too close to the motors electrical wiring.

Does anyone have any ideas? Will it help if I insulate the transducer wire? That's gonna be my first attempt to fix the problem.

Well... Back to the update. I trolled all over the lake for a few short strikes but no action other than that. According to some of the reports here... I was too deep early in the morning ( about 45' ).

At the end of the day I trolled by a couple of guys who were slayin on the bait n wait and they told me to anchor near them and have my kids throw cutbait on light tackle. We ended up picking up 4 Stripeys in our last half hour. Thanks to those guys for helping us beat the skunk. They were FNNrs... who rarely post according to them.

Thanks anyways...You know who you are. You put a :Big Grin: on the kids faces and saved me from more :Embarrassed:! Lol.

Here's a picture of a couple of the dinks....

28127

[Hometown]

You need a seperate battery that is what manufactures suggest due to interference from engine. and mount the tranducer at least a 1 1/2 ft froom engine.IMA
Well... While most of the boats at the MID on Saturday were slaying, I had a slow day, mostly fighting with my newly installed PiranhaMAX 160.:Embarrassed:

I installed it myself so I knew there could be some glitches. When I launched and turned the unit on it read the depth just fine at the dock so I was very happy.:LOL: But as soon as I started the engine the unit thought that there were fish everywhere.

Whenever the motor is shut off it gets true readings but when turned on there is intereference and it thinks that the lake is one big school of fish.:Confused: I mounted the transducer 16" away from the motor... instructions say 15" minimum. The only other idea I have is the transducer wiring is too close to the motors electrical wiring.

Does anyone have any ideas? Will it help if I insulate the transducer wire? That's gonna be my first attempt to fix the problem.

Well... Back to the update. I trolled all over the lake for a few short strikes but no action other than that. According to some of the reports here... I was too deep early in the morning ( about 45' ).

At the end of the day I trolled by a couple of guys who were slayin on the bait n wait and they told me to anchor near them and have my kids throw cutbait on light tackle. We ended up picking up 4 Stripeys in our last half hour. Thanks to those guys for helping us beat the skunk. They were FNNrs... who rarely post according to them.

Thanks anyways...You know who you are. You put a :Big Grin: on the kids faces and saved me from more :Embarrassed:! Lol.

Here's a picture of a couple of the dinks....

28127

[MustHuntAndFish]

Thanks Hometown,

I'll try the insulation first as I'll be out at the Mid this weekend with some cousins from Central Cali who would like to help thin out the stripers and hunt for some smallmouth also. Meanwhile I'll look at some 12 volt batteries on Cabelas or Bass ProShops if I find that a seperate battery is the answer.

Thanks Again1

[alpine8fisherman]

Thanks Hometown,

I'll try the insulation first as I'll be out at the Mid this weekend with some cousins from Central Cali who would like to help thin out the stripers and hunt for some smallmouth also. Meanwhile I'll look at some 12 volt batteries on Cabelas or Bass ProShops if I find that a seperate battery is the answer.

Thanks Again1

insulation? Not knowing what you had in mind, but shielding over your transducer wire with the shield grounded may improve the noise that you are seeing on the display. What motor you are running? What you are describing sounds like either the unit has a filter problem because most unit are design to operate with most outboard conductive interferences. Another condition such as motor noise suppression/condenser at the magneto not working properly will do the same. Check also that battery is properly grounded to the motor. You may try running the motor and your unit at home with a motor flush cups after your fix before heading out to the lake. It may save valuable fishing time instead of messing with it on the water. Hope that helps.

[naksa5]

Mount the transducer lower towards the water. I think I had same problem before.

[Hometown]

No proplem Bro I hope it works out for you let us know.
Thanks Hometown,

I'll try the insulation first as I'll be out at the Mid this weekend with some cousins from Central Cali who would like to help thin out the stripers and hunt for some smallmouth also. Meanwhile I'll look at some 12 volt batteries on Cabelas or Bass ProShops if I find that a seperate battery is the answer.

Thanks Again1

[MustHuntAndFish]

insulation? Not knowing what you had in mind, but shielding over your transducer wire with the shield grounded may improve the noise that you are seeing on the display. What motor you are running? What you are describing sounds like either the unit has a filter problem because most unit are design to operate with most outboard conductive interferences. Another condition such as motor noise suppression/condenser at the magneto not working properly will do the same. Check also that battery is properly grounded to the motor. You may try running the motor and your unit at home with a motor flush cups after your fix before heading out to the lake. It may save valuable fishing time instead of messing with it on the water. Hope that helps.

I originally zip tied the fishfinder wires to all the other wiring just to keep everything clean. Another FNNer PMd me and said separating the fishfinder wires could possibly be an easy fix so I ran the fishfinder wires separately inside plastic flex tubing. He also suggested ferrites if that didn't work.

The motor is a 100hp Merc. What exactly do you mean by grounding the shield?... please excuse my ignorance:Embarrassed: I have motor flush cups but the transducer can't read anything unless its submerged in water several feet deep. I guess I could still test it and I'll know if there's interference if it's reading fish anyway.

Thanks for the help guys.... I appreciate any other suggestions...

[TroutOnly]

Those guys are lurkers they were harassing me at the dock,,,,,turn down the intendecy,,,,,,,,you might just have to adjust it,,,,,,,,,,

[alpine8fisherman]

I originally zip tied the fishfinder wires to all the other wiring just to keep everything clean. Another FNNer PMd me and said separating the fishfinder wires could possibly be an easy fix so I ran the fishfinder wires separately inside plastic flex tubing. He also suggested ferrites if that didn't work.

The motor is a 100hp Merc. What exactly do you mean by grounding the shield?... please excuse my ignorance:Embarrassed: I have motor flush cups but the transducer can't read anything unless its submerged in water several feet deep. I guess I could still test it and I'll know if there's interference if it's reading fish anyway.

Thanks for the help guys.... I appreciate any other suggestions...

Need not be embarrass, my fault for not clarifying. Separating the wiring away from the other motor wiring as suggested by another FNN is a good practice. Ferrites is a good noise filter also. Those two suggestions are the quickest and easiest. There are metal shielding sleeve that one can slip over wire and then ground the shield to the negative side of battery. As you can imagine that is not an easy task. Is your unit + and - 12V connected directly to the battery and not to power point elsewhere? You do not have to submerge your transducer to determine if your fix has eliminated the noise, you should have a fairly clean display if your fix has eliminated it.
I was asking about the motor because some small manual start 2 stroke motor are electrically noisy, Good luck!

[Hometown]

Lurker ? really
Those guys are lurkers they were harassing me at the dock,,,,,turn down the intendecy,,,,,,,,you might just have to adjust it,,,,,,,,,,

[bassmeister]

What side of the outboard is the transducer mounted? When I installed my Hum Bird 797 si, manual said if your prop rotates clockwise, to mount the tansducer on the right side of the engine as you face the rear end of your boat, and to mount the transducer on the left side if it is a counterclockwise rotation. Good luck and hope you find and fix your problem as cheap as you can. Also make sure your tranducer is mounted so that no rises or (I think they are called strakes) won't cause for water cavitation that will have your transducer in turbulant water.