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Russell H.
Russell H., Service Tech
Category: Marine Electronics
Satisfied Customers: 11046
Experience:  8+ years of professional experience
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I have not had much luck wit Furuno Tech Support. Here goes.

Customer Question

I have not had much luck wit Furuno Tech Support. Here goes. I purchased a sail boat equipped with Furuno Navionics. All was operational when purchased last February. The boat did lie idle at dock for about 3 months. The house battery charger and the hot temps boiled off the house battery bank electrolyte and the charger went into boost mode holding DC line voltage at 18.5v. The NAVpilot 711 and the FI-50 multi's stopped working. The NAVpilot is now stuck in SIM mode and I cannot enter the setup menu to reset. The FI-50's only display --- regarding any data such as speedo or depth. I can enter their menus but they are not receiving any data for other instruments or transducers. All equipment is powered up and displaying. When I changed out the house batteries, I was hoping that the devices would reset. this did not happen. I have checked the processor board for the NAVpilot and it is displaying 2 green LED's. I have also check the connections on the CAN bus cables to these instruments and they all seem intact.
Submitted: 2 years ago.
Category: Marine Electronics
Customer: replied 2 years ago.
The boat is also equipped with a Furuno chart plotter, GPS, AIS and a MaxSea application loaded and connected on ship board desk top PC. These devices are working.
Customer: replied 2 years ago.
When I called Furuno Tech Support, he suspected a problem with the CAN bus. I have the CAN bus Network Design Guide manual No. FQ4-2009-006. The bus cables are directly wired to the MFD/Chart Plotter, NAVpilot-711 and the FI-50 multi's. There is no HUB-101 or NMEA-CAN bus interface unit. The PC apparently is equipped with a LAN router with CAT-7 cables. All indicator LED's illuminate in the green. The MaxSea does have an application called a setup wizard. This did run diagnostics and indicated that the FI-50's and the NAVpilot-711 were off line.
Customer: replied 2 years ago.
I will attached the emails received from the previous owner. He is more familiar with the system than I.Email-1: I do not think the Autopilot requires depth or speed data to function. I think it only requires GPS and wind data.
Check the GPS at the nav station is working. The NMEA 0183 GPS signal comes from the Navigation unit (Furuno GP 32 ) at the nav station. It has two outputs. One goes two the VHF radio. The second goes through a splitter which sends one signal to the Chart Plotter and one to the auto pilot processor. As this GPS outputs is a NMEA 0183 signal it has a dedicated wire to each unit. It does not connect to the NMEA 2000 Bus. Check that a GPS signal is being output either at the Navigation unit, VHF radio, AutoPilot or Chart Plotter. (Note the Chart Plotter uses the AIS GPS signal if the primary GPS signal fails from the Navigation unit).
If the Autopilot has no GPS signal/coordinates, check the wiring. I am not sure where the GPS NME0183 signal goes into the AutPilot - I think it is connected at the Autopilot processor unit.
If the GPS signal is not being sent from the Navigation unit the Chart plotter should automatically revert to the AIS GPS signal. (This can be checked in system setup). Regardless of the origin of the GPS signal the chartplotter can be used to control the Autpilot instead of the GP-32 Navigation unit. The input signal is selected from the Autopilot setup menu
The wind data, speed and depth are connected via the NMEA 2000 Bus, which is a single cable connecting between FI-50 Multi at Nav station, the autopilot processor, helm station gauges and chart plotter. If the Multi's show wind data, I think the NMEA2000 Bus is OK and this is not the problem effecting the Autopilot. (This is not the case. The FI-50's are not displaying any data) In respect to the speed/depth log check the wiring from the sensor in the port bow to where it connects the BUS - I think this is at the nav station multi display unit. Note the speed will not show if the paddle is fouled which happens frequently if the boat is not used for a few weeks - The depth should always show unless you are in depths greater than 100m or so (the transducers appear normal and are not fowled).
I am afraid I can't think of anything else to check. The only time the autopilot has not worked is when I forgot to switch on the GP 32 Navigation unit ! The antenna to the GP 32 Navigation unit failed once but the cahartplotter automatically reverted to the ais gps signal and the autopilot continued to operate normally - That is, as long as the Chartplotter and AIS were switch on ! This is when I learned how the NMEA system worked !!! and it took some time to understand !
Email-2: It sounds to me that Furuno may be on the right track and the problem is either the bus between the autopilot and the processor or the autopilot itself. I am not sure what you mean by SIM mode as I have not seen this before. I assume simulation mode ?
I know there is a button combination you press on the autopilot to get into installation setup mode. I don't think this is in any of the Furuno's manuals although I think I may have written down in one of my files I gave you. However, in this setup mode you may be able to do a complete reset but that may mean having to recalibrate the autopilot. May be Furuno can advise again on this.
Email-3: The autopilot only requires the GP 32 navigation unit, wind sensor and flux compass to operate. The Chartplotter, radar and AIS are not required and the autopilot functions 100% without them connected or switched on.The GP 32 unit is connected to the autopilot using a NMEA0183 single signal cable (no other way). The wind instruments and Compass ( I think) are connected through a NMEA2000 shared bus as is the autopilot head.AIS is connected via the LAN switch to the Chartplotter. Radar is connected via a CAT7 type cable to the chartplotter. The chartplotter is connected to the NMEA 2000 bus to read wind and speed sensors and to send only route data to autopilot if autopilot option to use such is selected.Therefore, the LAN/CAT7 system is not required to operate the autopilot. Incidentally, opto electric cabling is not an option, and the CAT7 cabling was supplied by Furono's main agent in France. There is no alternative with this model.All I can say is check NMEA 2000 bus cabling starting at Multi, at nav station, to Autopilot processor in owners cabin, electric compass under owners bed and then at helm station wind, multi, autopilot head and chartplotter.All the NMEA2000 cables ends have a screw bayonet fitting which are normally water tight and I would think reliable. May be a cable has chafet which you cannot see ? If wind data shows up at the helm and nav station then it would suggest any break could be between instruments, chartplotter and processor unit. I am not sure how you go about testing NMEA2000 cables with a multi meter but Furono may be able to give tips.
Customer: replied 2 years ago.
I have not checked the fluxgate compass. However, from the plotter, this appears to be operating and transmitting data to the MFD plotter and the MaxSea application running on the PC. Note, all devices are powered up. There is no data being received on the FI-50 multi's and the NAVpilot-711 is stuck in SIM mode and marches through demonstration screens. I have tried to enter the setup menu by powering up the control head, holding the button and then pressing the course select knob 3 times. I get a triple beep with each press but the device stays in SIM mode. Furuno tech support comments that the control head is not receiving data from the processor. Note, all these devices were fully operational and no one has tampered with the wiring.
Customer: replied 2 years ago.
I contacted Furuno Tech Support at 1-***-***-****. In addressing the NAVpilot-711 there are 3 reasons for the device to be in SIM mode.
1. Operator choosing SIM mode
2. No connection with the autopilot processor
3. Programming mismatch.
The most likely is that there is a connection interruption via the NMEA 2000 cabling. This could be a loss of power or a failed terminator resistor.
The FI-50’s displaying only suggest interruption in the NMEA 2000 cabling as well. To test, use a multimeter to “ohm-out” the data back bone and also check that the cabling is powered at 12 volts.
With the NavNet 3D, wind, speedo and depth data is not being displayed. If there is a connection but data is not being transmitted, then the data will display as . If there is no connection, the data will display as . If memory serves, the NavNet 3D displays , suggesting a loss in connection either through lost voltage or a failed terminator resistor.Refer to female connector diagram when testing.
So, to ohm out, the bus must not be powered and pins 4 and 5 should read at 60 ohms (this should be 120 ohms). If not the case, then a terminator resistor has failed and needs to be replaced.
When the bus is powered up, the voltage across pins 2 and 3 should read 12 volts. IF this is not the case, there is a loss in power at the “T” connector adjacent to a terminator. Note, the resistive terminator is 120 oms, ¼ w.
Note, FI-50’s can be connected in a daisy chain without the “T” connector. The network connection is made by two methods for all types of connectinos: a connector and barrier strips. The connections are used;
a. For connecting segments of back bone cable together
b. For connecting terminations at the two ends of the cable
c. For connecting the network power source, and
d. For connecting devices.
There are two types of the connector; “Mini” for heavy cable and “Micro” for light cable are used for NMEA 2000 network connections.
Barrier strips are only recommended when the connections are made in a protected location, or when they are installed in a weatherproof enclosure. Two methods may be used together in the same network. (I have not detected use of any barrier strips on Aluna).
Two types of cable are used in the network, heavy and light. Heavy cable is a five-wire construct with two individually twisted-shielded pairs enclosed by an overall shield with a shield drain wire connecting all three shields. This has a 10 mm diameter, MAX. 8A
Wire colors of heavy/light cable
Name Pair Color Size heavy/light Pin#
Shield Drain Bare 18/22AWG 1
NET-S Power Red 16/22AWG 2
NET-C Power Black 16/22AWG 3
NET-H Signal White 18/24AWG 4
NET-L Signal Blue 18/24AWG 5
Connector pin function
Pin No. Function Color
1 Shield Bare
2 NET-S (Power Supply Positive, +V) Red
3 NET-C(Power Supply Common, -V) Black
4 NET-H (CAN-H) White
5 NET-L (CAN-L) BlueT-Connector
There are two types of T connectors, Mini for heavy cable and Micro for light cable.
There are 4 types of 120 ohm terminators, male & female for Mini & micro cables. These connect across pins 4 and 5.
Note, Furuno CAN bus devices such aa the DRS, FI-50, GP-330B, SC-309 and WS-200 have an internal terminator so these can be connected to the backbone cable direct to either end without a T or terminator.
To activate the internal terminator on the FI-50, the terminal resistor is on and off through “Setup2” menu. To show setup2 menu, press the following two keys at a time until the menu appears.
FI-50 series To get into Setup2 mode, press To choose item, press
FI-501/502/505 3rd and 4th keys from left Mode
FI-503 Lower and SELECT/CLEAR Upper
FI-506 BRILL and left arrow key
(To save the change, press BRILL and left arrow key again) Right arrow keyNetwork Power Supply
The CAN bus can be operated at a 9.0 to 16.0 Vdc supply. Ensure that the voltage of the power supply to the device located farthest from the power source on the network is 9.0 Vdc.
The total current carrying capacity of the network depends on the choice of backbone cabling. Heavy cable is rated at 8 amps and light cable at 1 amp. These must be derated with temperatures exceeding 20°C. If the power connection is made at the center of the backbone cable, then the current carrying capacity is effectively doubled as the full capacity is available to each end of the network from the power connection point.
Expert:  Russell H. replied 2 years ago.
Hi, thank you for contacting My name is Russell. I will do my best to provide the right answer to your question.
Something in the network of instruments controls and network equipment has gone bad, for sure, I think.
I think this from simple electronics behavior, that undervoltaging can be as harmful as overvoltaging. And with the electrolyte boiled away in the batteries, you would have an undervoltaging by and by even with the charger in Boost mode, I would think.
Some devices are still working, obviously. But the networking equipment (aside from the LAN bridge with all green lights) and/or the NAVpilot 711 and the FI-50s, and one of them or all of them possibly, have not remained in working order.
The only way of settling this for sure is to either start swapping out equipment (an expensive way to do things!) or else to take one (or two or all) of the instruments that are not working, to a shop, and have the shop test them in an entirely different environment and with entirely different equipment, to see whether they survived functionally in all ways esp. networking and basic operation... or not. And go from the indication thereto.
Customer: replied 2 years ago.
I was hoping for an easy fix. The FI-50's are malfunctioning due to a problem with data transmission/reception in the NMEA2000 CAN Bus. Since all are powered, the drop down 12v supply is still functioning. That would leave either a malfunction in the FI-50 unit immediately adjacent to the RI-501 Wind or a problem with a Terminator 120 ohm resistor.
I can't figure out the FAP7011 data interrupt with the FAP7002 controller. Both devices seem to be powered up but will not share data with the NMEA2000 CAN Bus and will not communicate. Since heading data seems to be shared, I would surmise that this data is being transmitted on the NMEA0183 bus and, as such, has not been corrupted. I am not certain on the configuration on the connects between the autopilot control head and the processor but I suspect this is also NMEA2000. Since all units are apparently powered, I have to conclude that the data transmission has been corrupted and that a Terminator 120 ohm resistor has failed of the FI-50 device adjacent to the FI-501 Wind has some data sharing issues and will not pass through the data to other devices.
So far, your recommendation is obvious but will not solve the problem in the field. The boat is lying in Jamaica and there are absolutely no technicians in the region that can provide the needed expertise. Unfortunately, I was hoping for more.
Expert:  Russell H. replied 2 years ago.
Terminators can get burned out (e.g. in the circumstances you have mentioned), and are fairly cheap to replace. I would advise starting by replacing terminating resistors first, if you wish to start replacing anything. Also, since it was three months idle without maintenance, you might consider undoing the connectors - one at a time, and with the whole of the interconnected systems turned Off! - and scrubbing each connector or jack with a clean dry brush, then wiping the metal of each with a clean dry lint-free rag cloth until it shines, then re-connecting firmly, and on to the next connector. This needs to be done now and then, in order to keep corrosion from blocking signals or reducing them.