Grounding question Plate Alloy Boat

[ghunt]

I have a plate Alloy Boat
All my accessory wiring earths and outboard earth are connected to a grounding bolt through the hull. Battery Earths as well.
(As per Quintrex std Wiring.) There is no electrolysis or stray currents etc
I have an existing system 3 x Lowrance live units, Radar, Auto pilot etc all working fine no issues.
I'm fitting a TZ3 12 touch system. DFF3D and Scx20.
Should I be connecting the grounding screws (TZ3 and DFF3D) to the hull of the boat as well?..
Or try it first without them grounded.

 

[FishTech]

I would install them just like your current system. If the chassis grounds are connect with the Lowrance system, I would do the same with the Furuno system. Especially the DFF3D. It is very sensitive to external factors like noise or stray current. Pay careful attention to its transducer wiring guide.
If you find interference on the Furuno equipment, it will be easy to disconnect the chassis grounds and see if it changes.