NMEA2K Backbone placement

Thor's Outlaw

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Hey All, Ill need to start a NMEA backbone and was wondering where some of you have placed yours on an older Grady, I have an 02 228 and am looking for suggestions. Thanks
 

kirk a

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Not sure what you are really after. The backbone should be reasonably close to the equipment connected to it, and close to a power source. On my old Mako, I added it under the helm area. Powered through a fuse in a Blue Seas box. Behind or under the helm is most likely, but every boat is so different from a wiring perspective.
 

Thor's Outlaw

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Not sure what you are really after. The backbone should be reasonably close to the equipment connected to it, and close to a power source. On my old Mako, I added it under the helm area. Powered through a fuse in a Blue Seas box. Behind or under the helm is most likely, but every boat is so different from a wiring perspective.
Basically just fishing around for a good space to mount the backbone. I was thinking behind the helm but I don't think I have much space in there.
 

luckydude

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In my buddies' 1999 228, there is a clam shell behind the helm in the cabin. I have the same thing in my 2020 228. Mine has part of the NMEA 2K backbone there, I ran an extension up into my radio box as well.
 
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kirk a

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There also ain't much to a "NMEA Backbone", either. It sounds much more impressive than the lil' pile o parts you will have.
 
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Hookup1

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The backbone has to run to all devices in the boat you want to connect today. The buss has multiple T'ee connectors, extension cables and terminators on both ends. The buss is powered with a special connector. Devices connect to the T'ee via a short cable. You should also consider what you may connect in the future.

On my boat the powered NMEA connection is behind my Garmin display at the helm. The overhead Garmin unit connects to the NEMA bus with several T’ee connections to radio and GPS antenna. Buss runs forward to Fusion stereo and is terminated there. The other side of the buss runs aft thru rigging tube to the aft bilge. Both engines are tied in and terminated there.
 
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Hookup1

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This is a great example. Power connector (yellow wire) in middle. Device T'ee on either side. Terminators on both ends.

To extend the buss add more T'ee connection and extension cables as needed.

1719252671067.png
 
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luckydude

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This is a great example. Power connector (yellow wire) in middle. Device T'ee on either side. Terminators on both ends.

To extend the buss add more T'ee connection and extension cables as needed.

View attachment 34243
And if you extend the backbone up to the radio box like I did, don't be fooled into buying a "backbone cable". Those are beefy cables but it turns out for a short extension, under 20 feet or so, a normal cable works just fine. I am guessing that the beefy backbone cables are for big boats like a Viking or whatever and they are running the backbone to the rear of the boat.

For the 228, just a normal cable will extend the backbone just fine.
 
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Ky Grady

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Clamshell behind dash also on my 2004 228. I relocated it from behind panel under helm when I repowered and my FBW buss needed to occupy the space.

20200410_190502.jpg
 

Don Davis

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Now that we are on the NMEA 2000 network topic, I bought the Suzuki SDS to SMIS cable then the Suzuki Interface cable (yes the correct software version for my 2012 DF250). I plugged it all in, fired up the motor in the driveway back in March and everything worked fine on my Lowrance HDS, I could see the RPM, engine temp, hours, fuel burn per litres at idle, all cool. I take it out to the lake a couple weeks ago to clean off the wood dust as I was finishing the inside of my shop with the boat inside, turn everything on and the HDS does not recognize the Suzuki interface, NADA. Come home check all the connections from the motor to the backbone, check voltage at the buss under the dash, remove and clean the spade connectors/connections, still nothing. Try auto configure, refresh device list, NADA, very frustrating, checked on WWW, Hulltruth etc but still nothing, just crazy, has anyone experienced this before, I’m out of options, thanks.
 

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I know with my Yamaha F150's and Garmin 8612 chartplotter the engine page won't see the motors unless the key switch is on.

I would take the NMEA 2000 connectors apart and put them back together - tighten the cable nuts. Check both terminators too. Sometimes the computers lock up and need a hard reset. Remove power from engines (battery switches?) and unplug the chartplotter for 30 seconds and plug back in. Then try again.
 

Halfhitch

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Any chance you have a mouse that took a liking to the Suzuki cable. Is it a big job to pull it out and check it? Set up your game camera looking at some goodies in the cockpit of your boat at night to see if you have a squatter.
 

Don Davis

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Luckily my boat lives in my shop when not on the water so rodents shouldn’t be an issue as the cables and everything are only 3 months old. I did make sure the key was on when checking the device list for the Suzuki Interface recognition and rec-checked all the connections ie SDS to SMIS to NMEA etc, my last hope is maybe blown fuse under the cowling which I will check soon thanks for the advice, much appreciated. My main goal with the NMEA network was to get the fuel burn and diagnostic information on my Lowrance when needed to help troubleshoot any issues.
 

Hookup1

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Do you have anything else on the NMEA 2000 buss? Maybe a GPS puck?
 

Don Davis

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Actually yes, the boat had a Garmin external GPS antenna on the hardtop when I bought the boat, I never plugged it into anything until I setup the NMEA backbone. Do you think that Garmin GPS is interfering with the Lowrance HDS and the NMEA network?
The previous owner left the Garmin GPS receiver and must have had all Garmin electronics as I noticed the NMEA backbone is labelled Garmin. I had some other T’s that I wanted to use to extend the original backbone to add more devices but the tabs don’t line up so I ordered a new 4 port solid backbone. Just sucks how incapable different manufacturers of NMEA parts seem to be.
 
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Hookup1

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You could disconnect the Garmin GPS to see. Also look on the Lorance device list to see if you can see the GPS device.

NEMA stuff is very simple and compatible across the brands.

Try a hard power down before you panic. Maybe even a factory reset on Lorance. I had to do this to my Fusion stereo a few weeks ago.
 

Don Davis

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Will give that a try, I did notice that the device list only shows the Lowrance details now but previously showed the Suzuki Interface in the list, thanks
 

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Actually yes, the boat had a Garmin external GPS antenna on the hardtop when I bought the boat, I never plugged it into anything until I setup the NMEA backbone. Do you think that Garmin GPS is interfering with the Lowrance HDS and the NMEA network?
The previous owner left the Garmin GPS receiver and must have had all Garmin electronics as I noticed the NMEA backbone is labelled Garmin. I had some other T’s that I wanted to use to extend the original backbone to add more devices but the tabs don’t line up so I ordered a new 4 port solid backbone. Just sucks how incapable different manufacturers of NMEA parts seem to be.
Haha...the Garmin branded ones are turned 45deg...aggrevating unless all of them are Garmin....

Not familiar with the older Suzuki setup. But... My newer Zuke SMG4 gauges connect to N2k.
The N2k power is isolated from the Suzuki side of the backbone. This allows gauges to work on Key even if n2k is off.
So there is a fuses N2k power T on the other side of the isolator T.

The n2k power wires are 22gauge and don't crimp well to a terminal. Been a problem for me more than once.