Grounding sonar unit

Hey guys,

Thanks for all the input and suggestions on sealing transom holes for my new transducer, it was a big help.

Have another question now regarding the display. I’ve attached a picture here. On the back of my display there is a ring terminal with a ground symbol. I’ve never heard of or seen grounding directly to the display before so I’m puzzled. The installation guide mentions nothing about what/where/how to do this either.

As always, thanks for your help guys!

Nate

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I’m not an electrical engineer by any means…but I do know that when some equipment is linked together, it requires a grounding bond. Additionally, if electronics are installed in an environment where static shock is common, having a chassis ground prevents damage. I would refer to the installation manual for the best suggestion on what needs to be done

Thanks Randy. Any suggestion on where to run the ground wire to? The manual doesnt mention/explain anything related to grounding, so I’m at a bit of a loss.

What unit is that?

It’s a Garmin Striker Plus 9sv.

Nate, I was curious about this and did a little more research this morning. Probably more than enough information out there to really confuse a guy.

So, If your getting RFI or interference from a trolling motor, its suggested to do a ground loop and tie all the grounds together and chassis ground all your equipment. HOWEVER, some on board chargers don’t like that and will start blowing fuses or possibly burn something up. THEN, if your running 24 or 36V, ONLY tie in the main battery???? Part of it makes sense to me and I question the other. Back when I had my first aluminum boat, I was told by multiple people to never ground devises directly to the boat. Only use the two wire lead back to the supply battery.

I would send an email to Garmin and ask for their technical assistance on when and why to use that chassis ground. If you do and get a response, please share

Randy is correct when he says not to ground anything to the hull of the boat.
the reason is that you will increase the potential for stray current voltage leaking through the hull into the water and vice versa.
I am supplying one of many good links on this subject,this link explains the reason for sacrificial anodes and how/why they work as well as stray current problems when hooked to shore power with other boats docked near by that have electrical ” leaks “,especially when onboard items are grounded to the hull.

http://www.boatus.com/boattech/articles/marine-corrosion.asp

Randy Wieland wrote:

Nate, I was curious about this and did a little more research this morning. Probably more than enough information out there to really confuse a guy.

So, If your getting RFI or interference from a trolling motor, its suggested to do a ground loop and tie all the grounds together and chassis ground all your equipment. HOWEVER, some on board chargers don’t like that and will start blowing fuses or possibly burn something up. THEN, if your running 24 or 36V, ONLY tie in the main battery???? Part of it makes sense to me and I question the other. Back when I had my first aluminum boat, I was told by multiple people to never ground devises directly to the boat. Only use the two wire lead back to the supply battery.

I would send an email to Garmin and ask for their technical assistance on when and why to use that chassis ground. If you do and get a response, please share

Thanks Randy- Yeah, not quite sure what to make of it – appreciate you looking into it, though. I’ve got an aluminum boat, no onboard charger, just a 12v cranking battery stern that also powers accessories (livewell/lights/bilge/anchor) and a dedicated deep cycle up front for my trolling motor.

In the past, I never had any issues with interference on my sonar, so hoping that will still be the case. Took your advice and emailed Garmin support to see what they recommend.

Iowaboy1 wrote:

Randy is correct when he says not to ground anything to the hull of the boat.
the reason is that you will increase the potential for stray current voltage leaking through the hull into the water and vice versa.
I am supplying one of many good links on this subject,this link explains the reason for sacrificial anodes and how/why they work as well as stray current problems when hooked to shore power with other boats docked near by that have electrical ” leaks “,especially when onboard items are grounded to the hull.

http://www.boatus.com/boattech/articles/marine-corrosion.asp

Iowaboy you by chance in the Iowa City area? Thanks for the resource, will certainly check it out. Hoping I can just direct wire to my rear battery with no troubles.

I did some digging under my console and hooowah what a mess. Previous owners and shops have made a right mess under there, cant make heads or tails of it, so hoping it’ll work to just run a length of 12awg back direct to the battery just so I can get out and do a bit more fishin before it gets colder then try to clean up the wires next season.

Thanks again guys

Nate,straight west of you about sixty miles and south a wee tad.

wire directly to the battery with its own fuse and you will be fine,just remember to turn it off after use.

if you really want to straighten that rats nest out I will help you out but you have to have a place to do it in and a game plan of what you want to do as it can take a couple of days at worst,weekends work best but the next several are tied up at the moment,a bottle of number seven wouldnt hurt either lol.

shoot me a pm when you think you want to do it.