How to Connect Garmin GPS to VHF DSC

by Will Charpentier

The Garmin GPSMap 3000 (or higher) Series Global Positioning System (GPS) receiver/chartplotter can be interfaced with a DSC/VHF marine radio with a single NMEA (National Marine Electronics Association) cable. The NMEA cable will come without data connection links, which you must connect to the cable. The link between your radio and your GPS will provide accurate Digital Selective Calling (DSC) information and limited Automatic Identification Service data to your GPS screen, if your GPS has that capability.


Make the required terminations between an NMEA barewire cable and an NMEA data connector link. Terminations are electrical connections that add a "plug" to the end of a wire. The terminations for Port 1 of the GPS unit are made by using the soldering gun and silver solder to solder the brown wire in the NMEA to Pin 16 (Data In) of the data connector link for the GPS. The blue wire should be soldered to Pin 17 on the same data connector link, the Data Out pin for Port 1.


Make the terminations for Port 2 of the GPS unit by soldering the violet wire, Port 2's Data In wire, to Pin 9, and solder the gray wire to Pin 10, the Port 2 Data Out on the data link connector for the GPS.


Make the terminations for the VHF/DSC radio according to the installation instructions for the make and model of NMEA 2000-compliant VHF/DSC radio.


Line up the notch on the locking ring of the terminated cable with the key on the NMEA port on the back of the GPS unit. Push the cable into place in the port and turn the locking ring to the right, until it stops.


Align the notch on the ring of the other end of the cable with the key on the NMEA port of the VHF/DSC radio; push the cable into place in the port and turn the locking ring to the right.


  • check VHF/DSC radios based on the "NMEA 0183" standard cannot be interfaced with marine electronics or NMEA networks based on the "NMEA 2000" standard without a special gateway device that allows intercommunication between the two standards.


  • close This activity requires that you terminate electrical wires by soldering them.

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About the Author

Will Charpentier is a writer who specializes in boating and maritime subjects. A retired ship captain, Charpentier holds a doctorate in applied ocean science and engineering. He is also a certified marine technician and the author of a popular text on writing local history.