Garmin 7410 xsv Interference issues

[Moffy]

Am having issues with interference (appears to be electrical) in my 7410xsv.

Have re-routed the transducer away from power cables and that made an improvement but still not perfect.

Am currently trying sourcing power from a battery not connected to the motor to see if that is an improvement but won't get a chance to test on the water for a few weeks.

The manual indicates that you can connect a post on the back of the unit to the "water ground" to help with interference. Not sure I want to hook anything up to my alloy hull with electrolysis etc - is it possible to connect this post to the negative post on the battery and achieve the same effect (with no adverse issues)?

Cheers,

Moffy.

[PROS]

What is the actual issue?

Interference more pronounced when you apply power to engine and less on idle/low speed?

[Moffy]

Hi Pros,

yes that's pretty much it.

Though it's mainly concentrated on the side scan. a few hundred revs makes a clearly discernible change and is instant even though boat speed has barely changed. I can otherwise maintain a bottom image on the "normal" sounder at 30knots. ( hence why I don't think it's transducer location related (also easier to trouble shoot electronic interference first before I start drilling new holes to relocate the transducer (and it's a plate boat with no strakes - so it's all pretty similar in terms of clean flow to the transducer.

weirdly It also seems to get worse over time on the water eg as the battery heats up - hence why I'm concentrating on that first.

The bit from the installation manual I'm referring to says


Additional Grounding Consideration
This consideration is applicable only to devices that have agrounding screw. Not all models have a grounding screw.This device should not need additional chassis grounding inmost installation situations. If you experience interference, thegrounding screw on the housing can be used to connect thedevice to the water ground of the boat to help avoid theinterference.


Just keen to know whether I can hook the grounding screw up to the negative on the battery ( as opposed to the "water ground" ) without causing any issues to see if this helps with my interference ( but will also be doing the other things I mentioned above re separate battery etc)


Moffy

[Fed]

Give it a rev in neutral and see if you get any interference.

[PROS]

Hi Pros,

yes that's pretty much it.

Though it's mainly concentrated on the side scan. a few hundred revs makes a clearly discernible change and is instant even though boat speed has barely changed. I can otherwise maintain a bottom image on the "normal" sounder at 30knots. ( hence why I don't think it's transducer location related (also easier to trouble shoot electronic interference first before I start drilling new holes to relocate the transducer (and it's a plate boat with no strakes - so it's all pretty similar in terms of clean flow to the transducer.

weirdly It also seems to get worse over time on the water eg as the battery heats up - hence why I'm concentrating on that first.

The bit from the installation manual I'm referring to says


Additional Grounding Consideration
This consideration is applicable only to devices that have agrounding screw. Not all models have a grounding screw.This device should not need additional chassis grounding inmost installation situations. If you experience interference, thegrounding screw on the housing can be used to connect thedevice to the water ground of the boat to help avoid theinterference.


Just keen to know whether I can hook the grounding screw up to the negative on the battery ( as opposed to the "water ground" ) without causing any issues to see if this helps with my interference ( but will also be doing the other things I mentioned above re separate battery etc)


Moffy

Moffy,
I dont know the answer to your issue but I also have the similar problem.
Used to have lowrance sounder which the interference was very bad, thought it was the sounder/transducer combo and replaced with Garmin and still have the issue although significantly less which I can read the screen now at least.

On idle sounder works great.
As I apply power, significant interferance shows up on the screen as a thick black line than settles down to less but still visible clutter on the screen.
This happens both normal sounder and side scan.
Speed is irrelevant.
Will get a video of it next time I will be out

I tried using a battery completely isolated from the boat, problem still exists.
Tried running transducer wiring on different location, still happens.
Was thinking to replace +/- bus blocks just to see if it helps. Also to replace switch panel just as general maintenance.

Fed's suggestion is interesting, I havent tried to see if it happens on neutral.

Max

[swof63]

If it doesn't happen in neutral even with a rev you may be seeing your pro when in gear. Used to have that.

[swof63]

Prop. Sorry.

[PROS]

If it doesn't happen in neutral even with a rev you may be seeing your pro when in gear. Used to have that.

Prop is in the transducer signal cone area, did I understand correctly?
If so tilting the leg up should also eleminate the problem.

I am assuming you relocated the transducer to further right or down to solve the problem?

[Moffy]

Thanks guys - still a couple of things to try - will let you know Pros if I find an answer that might work for you.

[swof63]

Prop is in the transducer signal cone area, did I understand correctly?
If so tilting the leg up should also eleminate the problem.

I am assuming you relocated the transducer to further right or down to solve the problem?

Yes. Problem was worse with 50 than 200 ( wider cone) and side scan was bad not surprisingly. Tilting motor definitely improved it. Relocated transducer further right ( ally boat not too much dead rise so was effective ) and canted it a bit away from the prop so it wasn't quite parallel with the sea floor. Still worked okay and less noise.

Cheers