Re-using NMEA0183 Connections from Old DSC VHF to New DSC VHF

Hello,

Just getting ready to upgrade the VHF radio in my 280 and I'm contemplating whether to re-use the original wire plug for power/NMEA0183. The old radio is a Raymarine Ray215 and the new one is a Standard Horizon GX1800. The chartplotter is a Garmin GPSmap182c.

Looking at the white connector, I see 6 pins. Two for 12V, green and yellow for speaker (?), and purple and blue for NMEA in to VHF. I found these assignments from the Ray215 manual. I assume that in this setup, there isn't an NMEA out from VHF to Garmin.

The main reason I want to re-use the connector is so I can setup/connect the wiring at home, then go to the boat to plug everything in. Also having just NMEA +- from Garmin to VHF would simplify things for me as I don't need to send NMEA to the Garmin.

So the plan is to connect the existing wires to the standard horizon harness black to black, red to red, blue to yellow, purple to green.

Just wanted to run this by to make sure I'm not making any obvious mistakes in my logic. Really feels good having a group to consult for my projects on this boat.

Existing Connections:

Standard Horizon GX1800:

Garmin GPSmap 182c:

Raymarine Ray215:

That looks exactly correct, did a similar thing on my boat going from northstar to Simrad and standard horizon...

I'm confused, so I hope I'm not just messing up a solution you already have, but assuming the SH isn't an 1800G and you need GPS from the Garmin, wouldn't you need the Garmin White, which is TX (out)?

As far as out from VHF and into Garmin, I agree that's not a need, but there's definitely value to it. Incoming Distress calls and position requests can be shown on the plotter screen.

Todd320 said:

That looks exactly correct, did a similar thing on my boat going from northstar to Simrad and standard horizon...

Click to expand...

Great! Good to hear another member has completed a similar upgrade.

RollerCoastr said:

I'm confused, so I hope I'm not just messing up a solution you already have, but assuming the SH isn't an 1800G and you need GPS from the Garmin, wouldn't you need the Garmin White, which is TX (out)?

As far as out from VHF and into Garmin, I agree that's not a need, but there's definitely value to it. Incoming Distress calls and position requests can be shown on the plotter screen.

Click to expand...

Looking at the Garmin wiring diagram, it does look like they want the white wire going to the VHF. Funny how I don't have a white wire going to that 6 pin plug. Calling off the project until we get this figured out. Don't want to damage the chartplotter.

Ah I see! I assumed my chart plotter was too old to utilize that function. Explains why it has NMEA in. I was originally going to buy the GX1800G, but knowing that my mounting position is quite low on the helm, I opted against it as I believed my GPS signal would be more reliable with the NMEA connection. Don't know if it's worth the gamble to get the GPS built in, risking a bad signal.

Thanks for the info.

Looking at the diagram again, I see the white wire is labeled as RTCM/NMEA in. The green wire (Garmin-side) plays the same role as the blue wire as NMEA out, just on a different COM. Looks like Garmin designed this chart plotter to be used with an assortment of NMEA dependent components simultaneously hence the multiple NMEA outputs. To me, the original wiring plan makes sense with that considered, but I still don't know whether the blue or green wire should be connected to the Standard Horizon.

Garmin _ _ _ _ _ Radio
+green, out => Yellow +, in
+white, in. <= white +, out

Battery _ _ _ _ _ _ Radio
-black _ _ To _ _ _ Green,- in
-black _ _ to _ _ _ Brown, - out

This ignores the picture of the connector, this is just, garmin, battery, to the radio and back. I was referring to the connector before (and confused myself). regardless of what is in between, just make sure the green on garmin goes to the yellow on radio, as laid out above, Etc.
Note, the - in/out on the radio are just connected to ground, per the diagram from Garmin. I literally connected all four together, green- and brown- And black- from radio to the black- from battery.

you can technically use the other NMEA in/outs mentioned by Garmin (Blue out, Brown in), but use the ones specified for the radio, the others probably support much higher baud rates needed to connect with an AutoPilot and other critical consumers/providers.