Step 2: Connect the GXM 51 Antenna to Your NMEA 2000
Network
The GXM 51 is packaged with a NMEA 2000 T-connector and a NMEA 2000/audio cable. You
will use these two components to connect the GXM 51 to your existing NMEA 2000 network.
If you do not have an existing NMEA 2000 network, you will need to install a NMEA 2000
network on your boat. For more information on NMEA 2000, visit www.garmin.com.
To connect the GXM 51 to your existing NMEA 2000 network:
1. Determine an appropriate
location to connect the
GXM 51 to your existing
NMEA 2000 backbone.
2. Disconnect one side of a
NMEA 2000 T-connector from
the backbone nearest to the
location where you want to
connect the GXM 51 antenna.
If you need to extend the
NMEA 2000 backbone,
connect an appropriate
NMEA 2000 backbone
extension cable (not included)
to the side of the T-connector
you disconnected.
3. Connect the included
T-connector in the NMEA
2000 backbone.
4. Route the NMEA 2000 portion
of the NMEA 2000/audio cable
from the GXM 51 antenna to
the top of the T-connector you
added to your NMEA 2000
network.
The 19 ft., 6 in. (6 m) NMEA 2000 portion of the NMEA 2000/audio cable is the maximum
length for a drop cable as defined by the NMEA 2000 standards. If more cable is needed,
add an extension to your NMEA 2000 backbone, based on the NMEA 2000 guidelines.
Step 3: Connect the GXM 51 Audio Cable
To hear XM Radio through the stereo on your boat, connect the audio adapter cable to the audio
portion of the NMEA 2000/audio cable and to an audio input on the stereo. Refer to the manual
provided with your stereo for audio input installation and operation.
Step 4: Update Your Chartplotter
To ensure compatibility with the GXM 51, upgrade your Garmin chartplotter with the latest
software. A GPSMAP 4/5000 series chartplotter must be at software v5.0 or later to use the
GXM 51. For more information, visit http://www8.garmin.com/support/download.jsp.
GXM 51 Installation Instructions
NMEA 000
NMEA 000
device
device
(not included)
(not included)
T-connector
T-connector
(included)
(included)
Existing NMEA 000 network
Existing NMEA 000 network
(not included)
(not included)
GXM 51
GXM 51
antenna
antenna
NMEA 000
NMEA 000
(not included)
(not included)
NMEA 000/
NMEA 000/
audio cable
audio cable
(included)
(included)
To boat
To boat
audio
audio
device
device
5