NMEA 2000 adapter for GFL™ 10 fluid level sensor

The Garmin GFL 10 adapter is designed to modernize existing onboard systems by converting analog fluid level sensor data into NMEA 2000 digital data. It allows traditional sensors (whether connected to an analog gauge or directly to the fluid sensor) to be integrated into an NMEA 2000 network, enabling fluid levels to be displayed on compatible Garmin screens.

The GFL 10 adapter can be configured to monitor levels of multiple fluid types, including:

FuelFresh waterBlack waterOilLive wells

The GFL 10 adapter has a maximum power consumption of 1 W. Its Load Equivalency Number (LEN) on the NMEA 2000 network is 2, corresponding to a current of 100 mA.

Yes, the GFL 10 adapter complies with IEC 60529 IPX7. This means it can be temporarily immersed to a depth of 1 meter for up to 30 minutes. It is therefore suitable for marine environments exposed to splashes and washdowns, but must not be installed where it would be regularly submerged.

The GFL 10 adapter is powered directly via the NMEA 2000 network bus. It operates with a DC voltage range of 9 to 16 V (nominally 12 V DC).

The GFL 10 adapter can convert analog sensor outputs using 0-5V or 0-250 ohm ranges into NMEA 2000 messages.

The GFL 10 adapter uses the NMEA 2000 PGN 127505 message, which is specifically dedicated to fluid level monitoring.

The GFL 10 adapter has a Load Equivalency Number (LEN) of 2, which represents a 100 mA current drawn from the NMEA 2000 network. This figure is important for calculating the required power and balancing your NMEA 2000 network.

For installation of the GFL 10 adapter, you will need the following tools and supplies:

Heat-shrink tubing and a heat gunCable tiesAdditional NMEA 2000 wiring and connectors (optional)Screws (not included) may be required if you choose to mount the adapter to a bulkhead.

When choosing the installation location for the GFL 10 adapter, consider the following points:

It must be located within 4.4 meters (173 inches) of the analog gauge or fluid level sensor. It must be positioned between the NMEA 2000 backbone and the gauge or sensor. Install the adapter at least 5 cm (2 inches) away from a magnetic compass to avoid electromagnetic interference. Although waterproof (IPX7), do not install it in a location where it would be regularly submerged.

If your boat has an analog gauge, you can wire the GFL 10 adapter directly to it. Refer to your boat’s owner manual or the sensor manufacturer’s documentation to identify the ground, sensor, and power (contact) connections on the gauge. Wiring the GFL 10 adapter to the gauge must be done as follows:

Blue wire: Connect it to the sensor terminal (usually marked S or G). White wire: Connect it to the gauge’s power supply (usually marked +, +12V, I, or IGN). Black wire: Connect it to ground (usually marked -, or G). The yellow and red wires remain unused in this configuration. After connection, cover exposed wires with heat-shrink tubing.

If your boat has no analog gauge, you can wire the adapter directly to the fluid level sensor. Consult your boat’s owner’s manual or the sensor manufacturer’s documentation to identify the sensor’s send and ground terminals. Wiring the GFL 10 adapter to the sensor must be done as follows:

Blue wire: Connect it to the sensor terminal (usually marked S or G). Black wire: Connect it to ground (usually marked -). The white, yellow, and red wires remain unused in this configuration. After connection, cover exposed wires with heat-shrink tubing.

Yes, a specific precaution is required. When connecting the GFL 10 adapter directly to a fuel tank sensor, ensure you connect it to the tank sensor before plugging the adapter into the NMEA 2000 network. This reduces the risk of sparks near the fuel tank.

To connect the GFL 10 adapter to your existing NMEA 2000 network:

Determine the connection location on the NMEA 2000 backbone.Disconnect one side of an NMEA 2000 T-connector from the backbone.Add the included T-connector for the GFL 10 adapter to the NMEA 2000 backbone by connecting it to the disconnected side of the T-connector.Connect the NMEA 2000 connector of the GFL 10 adapter to the new T-connector.If the GFL 10 adapter cannot connect directly to the backbone, you can use an NMEA 2000 drop cable (not included) up to 6 meters (20 feet) long to connect it to the T-connector.Ensure only one power source is connected to the NMEA 2000 network.

Yes, you can use a drop cable to connect the GFL 10 adapter to the NMEA 2000 network if a direct connection is not possible. The maximum allowed length for a drop cable is 6 meters (20 feet).

Fluid type and tank number configuration is done via a Garmin display compatible with your NMEA 2000 network. In the list of NMEA 2000 devices, select the GFL 10. You can then choose the fluid type (fuel, fresh water, etc.) and assign a unique tank number if you have multiple tanks or GFL 10 adapters.

To calibrate the fluid level, you must use a compatible Garmin display and follow these steps:

Turn the boat's ignition key to the ON position (do not start the engine).In the NMEA 2000 device list, select the GFL 10.Access the level calibration menu (usually 'Level Calibration').Add a calibration point ('Add Calibration Point').Select the current percentage of fluid in the tank and confirm.Change the fluid level in the tank.Repeat steps 4 and 5 to add a second calibration point. A minimum of two points is required, but more points improve reading accuracy.

If the fluid level reading on your Garmin display changes with engine RPM, the GFL 10 adapter may be detecting an incorrect gauge type. To fix this:

With the boat stationary, put the engine in neutral.Increase engine RPM. If the fluid level reading changes, adjust the gauge type.In the GFL 10 configuration menu on your Garmin display, go to 'Gauge Type'.Select the appropriate option: 'Auto Detect', '1 Coil', or '2 Coil'.Repeat the test to confirm the issue is resolved.

The GFL 10 adapter is designed to display fluid level information on compatible Garmin multifunction displays (MFD) and displays. This includes devices such as the GPSMAP series or the GMI 10 display. For a complete list of compatible devices, you can consult Garmin's website.

No, the GFL 10 adapter is specifically designed to integrate into an NMEA 2000 network. NMEA 2000 is a plug-and-play communication standard for marine equipment and is considered the successor to the NMEA 0183 standard.