The Panbo Forum

Return to Panbo Forum main page »


NMEA 2000 Advice

Vote 0 Votes

Looking for a little advice and/or guidance. I have a Garmin NMEA 2000 backbone network which is currently feeding my GNX Wind Wired Sail Pack. That includes both the wind sensor along with a thru hull transducer and 2 separate instrument displays at the helm.

I picked up a Garmin 547 GPSMAP which is NMEA 2000 as well with the intent of simply plugging it into the backbone. Since the backbone is already fed power, I figured it would draw from that.

As a quick test, I unplugged one of the instrument displays at the helm and plugged it into the 547 GPSMAP. Unfortunately I got nothing. No power, nothing.

I'm sure I'm missing something but not sure what? The install guide is not helpful at all.

Thanks in advance.

s/v Gypsy Soul

6 Replies

  • Dan, only very low power draw devices can be powered off an NMEA 2000 network. You should have gotten a power/data cable with the 547 and you need to hook it up. Page three of the install guide the red and black wires you'll use.

  • Thanks Ben. The only cable that came with the 547 is for a 0183 network, however, there is also a 2000 connection but you supply your own cable.


  • Right, but that's an 0183 AND power cable, very common on displays like this. That's why you see an inline fuse on the red wire (unless removed by previous owner). Like I tried to say, attach red wire to 12v plus and black wire to ground and the 547 should work.

  • OK sounds good, I will give it a try. So deceiving because the NMEA 2000 network has 12V going through it as well and the whole concept is plug-and-play into the backbone. Very odd!

  • Gees, Dan, you're scaring me. Your presumption demonstrates gross ignorance about what NMEA 2000 was designed to do and how its working on boats all around you. Moreover, how to power that 547 is pretty clearly explained in Garmin's short installation manual.

    I think you need to be very careful about DIY installations, and to think thrice before blaming someone else for any problem you run into. Sorry to be rude, but I really am hoping you have more actual knowledge of navigation and seamanship, a better sense of what you don't know, and a greater ability to learn it.

  • Don't be scared Ben, it's all just networking fundamentals which I have an above-average skill in so I'm sure I'll work though it. The problem is that the marine industry is only incrementally moving forward in basic networking and currently living between two standards.
    The fact is that NMEA 2000 backbones which are connected to a 12V source have the ability to power "some" devices and not others. Unfortunately GARMIN does not clearly label this fact on the 547 install manual. However, all of my other GARMIN instruments including the hull transducer, 2 separate displays, and the computer control box are powered through the network, and it's simply a matter of time until they improve the cabling to push enough power through the network to all devices. Unless you are connecting "backwards" to other 0183 devices, there should be no technical reason to use that port, especially not just for 2 wires feeding power, that's just clearly an in-between standards design flaw.

    Don't worry Ben, I don't blame others for my temporary knowledge gap, that's why I'm posting on here to close that gap. I've spent the past 32 years of my life leading hundreds of men and women around the world in 3 separate wars, ensuring thousands of others died for their country or belief so that we can protect ours, so I don't suspect that the installation of a GPS unit on a small pleasure craft will be a major life event. And certainly not an event that requires an "installer." I think YouTube is doing a pretty good job already at exposing the secrets behind the curtain in many areas, and so it will for marine electronics installation.

    Thanks again for your input. Fair winds.