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Sonar Module Troubleshooting
Garmin sonar modules (such as the GCV series, GSD series, and the Panoptix LiveScope GLS 10) have an LED status light that indicate if an error has taken place and what has caused it. After identifying the source of the issue, click the relevant step below for troubleshooting instructions:
Note: If the error light or chartplotter indicate that a transducer is not detected, see No Depth/No Sonar for troubleshooting instructions.
Power issues
For instructions to troubleshoot power issues, click the steps below.
Check the fuse
Check for a blown inline fuse on the red wire of the power cable. If it is difficult to see whether the wire is intact, connect a multimeter to both ends of the fuse and measure for resistance. A good fuse would show close to 0 ohms on the multimeter.
Some multimeters have a continuity setting to check for blown fuses. These multimeters will emit an audible tone if the fuse is working.
Check the power supply
- Charge the battery fully, then remove the battery from the charger and wait 12 hours before testing the battery with a voltmeter. The engine must not be running while testing the battery.
- The ideal voltage is over 12 V. If the voltage is lower, the battery does not have enough power to run the sonar module and will need to be replaced.
- ??? amp draw
- If the power cable is connected to a panel or a switch, temporarily connect the power cable to a fully charged 12-volt battery to see if the sonar unit powers on. If the panel or switch has other devices connected, the sonar unit may need to be moved to a different panel or switch.
Check power cable and wiring
- Inspect the power cable and wiring system for any loose or damaged wires, faulty termination points, incorrect terminals, etc.
- If the wire is corroded at the termination points, cut the ends of the wire at both power and ground, strip back the sheathing, and rewire the new ends. If this is not possible, the power cable will need to be replaced.
- Check the voltage on the power cable connector head using a voltmeter or multimeter. The preferred voltage is over 12 V; a lower voltage may not be sufficient to power the module.
- If using a multimeter, set it to DC. Consult the multimeter's owner's manual if you are unsure where this setting is on the multimeter.
- If the module is connected to a fuse panel or wire block, temporarily connect the sonar module directly to the battery. If the module then powers on, it may have been connected to the panel or block incorrectly, or the panel or block may need to be replaced.
- If extension wires are being used between the module and power source, ensure that the correct gauge is used for each wire. Lower gauge numbers allow for a greater amount of power to be transferred. [[NOTE TO REVIEWER: should we disclose our own power cable gauges here?]]
- Check the brass contacts on the power cable connector head and the module's power port for tightness and corrosion.
- If there is light corrosion on the brass contacts, this can be cleaned with a brush and dielectric grease.
- If there is extensive corrosion on the power cable connector head, the corrosion may have extended into the cable itself. The power cable will need to be replaced.
- Extensive corrosion on the module's power port indicates possible damage to the sonar module. The module will need to be replaced.
Check for voltage drop
Check for voltage drop
What’s an excessive voltage drop? On boats the ABYC (American Boat Yacht Council) dictates a maximum voltage drop is 3% for critical circuits. What is considered critical? Circuits used for navigation lights, bilge pumps, VHF radios, GPS, radar (devices and systems that will bring the boat safely back to port).
Powers off when Cranking Engines or Increasing Speed
Advanced Voltage Test
- Verify that the device is connected properly. Verify ground wire is not loose or has corrosion build up.
- Use a volt meter on the bare wire end of the power cable, where it is connected to the power source.
- Watch the voltage readings on the meter, at the same time try to power on the device. You will either see a steady reading or a drop-in voltage.
- Voltage Drop - If the voltage drops when the device tries to power on, there is not enough power getting to the device. Examples when powering on the engines or increasing speed the device powers off. Try wiring the device directly to a new power source.
- Steady Voltage - If the voltage readings are steady, please contact Product Support.
Other Causes of Voltage Drop
- Follow steps above for Testing the Battery – note volts.
- Switch on the circuit to be tested. Connect your volt meter to the power cable connector head (add 8 pin/4 pin and 2 pin power cable pinout).
- Deduct the power cable volts from the battery voltage. Divide the sum by the battery voltage (move the decimal point move to show the percentage).
Example: Battery Volts 13.3
Power Cable Volts 11.9
Balance 1.4 / 13.3 = 0.1052631579 Move the decimal point over 2 and the drop is more than 10%
Marine Network issues
Check to see whether the chartplotter detects the sonar module over the Garmin Marine Network:
- On the home screen, select Settings
- Select Communications
- Select Marine Network or Garmin Marine Network
- Select Device List
If the sonar module is shown in the list, ????.
If the sonar module does not appear in the Marine Network device list, follow the troubleshooting steps below.
If using a GMS 10 Network Port Expander, check the LEDs above the ports to which the chartplotter and module are connected. If the LEDs are not blinking, meaning that no network connection is detected, follow the troubleshooting steps below.
- Update the chartplotter system software.
- Inspect both ends of the marine network cable [[NOTE TO REVIEWER: I checked the style guide and am not sure whether 'marine network' should be capitalized when referring to the cable or port]] for corrosion or damage.
- If the cable ends have recently been replaced, refer to the Marine Ethernet Installation Instructions to ensure they were properly installed.
- If possible, check the cable for continuity using a network cable tester or a multimeter. If there is no continuity, repair or replace the cable.
- To purchase a new marine network cable, search for the sonar module model on garmin.com, click Accessories, then click Garmin Marine Network.
- If the chartplotter and/or sonar module have multiple marine network ports, test the marine network cable with each port to see if the module appears on the Marine Network device list. If it does, a specific Marine Network port may be defective. [[NOTE TO REVIEWER: should we recommend a device replacement? Should the chartplotter be turned off while moving the cable from port to port?]]
After following these steps:
- If the sonar module is detected on the Marine Network page, update the system software. See Garmin Marine Device Software Updates for more information.
- If the sonar module is not detected, contact Product Support to set up a module replacement order.
Troubleshooting the Marine Network Connections
Check Marine Device List:
- Settings Select Communications
- Select Marine Network or Garmin Marine Network
- Select Device list
To quickly troubleshoot the marine network, take a new Marine Ethernet cable and plug into the sonar and directly to the chartplotter. If the sonar shows up on the chartplotter with a testing cable the below instructions will advise on how and what to look for on the installed network cable.
- Inspect the network cable running from the chartplotter to the sonar unit for damage at both ends. If possible, check the cable for continuity with a network cable tester. If the cable ends have recently been replaced, refer to the Marine Ethernet Installation Instructions to ensure proper installation. If the cable is faulty, repair or replace as needed. If the radar is connected to a device that has multiple network ports, try a different network port on the device.
- If a GMS 10 is installed, check the LEDs above the ports on the GMS 10 where the radar and chartplotter are connected. The LEDs should be blinking. If the LEDs are not blinking, check the network cable running from the chartplotter and/or radar to the GMS 10. Try connecting the radar/chartplotter network cable to a different port on the GMS 10. Repair or replace the network cable as needed. If the GMS 10 has a bad port, contact Marine Product Support to setup a repair.
- Finally, connect the radar to a compatible, working chartplotter and turn on the device. If the radar does not appear on the network list of this device, the radar will need to be repaired. Contact Marine Product Support to setup a Return Merchandise Authorization (RMA).
Update the Software
If the sonar is now being seen on the Marine Network Update the Software