NavPilot 500 just lost RRU signal/sensor

[musicmanjer]

Aloha Furuno Wizards,

I have a NavPilot 500 system. We had a Tsunami threat so we took our boat offshore last week. The autopilot was working just fine. We came in safely, but the very next day I get a Rudder Sensor error on my display. I checked connection to the system controller and then I checked connections at the FAP 6112 sensor. I re-spliced (soldered and heat shrink) connections again at sensor ( I replaced an old FAP-6110 and used the wire from it) and checked operation again in case there was water intrusion or corrosion. Nothing. It seems since it is an analog potentiometer, it would have some feedback and not just stop working altogether?

Is there a way to test the sensor via ohm meter? Could the controller have a bad connection at the connector? What are some tests I can do to diagnose?

I depend on AP for fishing almost every day. I ordered a tested used FAP 6112 and 511 processor from a boat electronics upgrade as it is a critical tool for us. Am I missing anything??

Mahalo, Capt Jerry

 

[Johnny Electron]

Hi Jerry, Please see attached.

 

[musicmanjer]

Johnny youre a Rockstar! Exactly what I needed!

Mahalo, Capt Jerry

 

[musicmanjer]

Aloha Johnny,

Ok I went through and checked resistance on the RRU. Center seems to be 960 ohms on one pair and 970 on the other. Pretty close. I checked Hard Port and Hard Starboard. They read 670 and 1310 respectively. These readings were made at the plug at the processor as to rule out an issue with wiring. I went ahead and reconnected everything and powered on the units. Still says error, so I went through the Rudder sensor setup again from Dockside Setup from scratch. It began reading the rudder and was able to do the Rudder center adjustment (+- 2 degrees). I did the Sea Trial and got the rudder limits set and will do another test to see if it indeed kept the settings held and will do a true sea trial on Monday with the unit. I will report back to my findings. It seems very strange that the processor lost the RRU functionality all of a sudden without any warning. We didn't have any variance in voltage that would cause a failure that I could notice. Have you known or seen any other units that behaved this way??

 

[Johnny Electron]

Tons of of things like EMI noise into the RRU cable can cause problems with the signal. Ensure that you are hard over when setting the port number and hard over the other way when setting the starboard number. Always set the center last.

 

[musicmanjer]

Ok I already did that in the order you suggested. EMI causes lots of issues and I am aware of that factor with other equipment. I have see VHF radio transmitting at 25 watts scramble all kinds of things, but I believe the cable from RRU is shielded which helps that issue. I will keep you posted on progress.
Thank you again.

 

[musicmanjer]

Ok, the settings did not store and it is still saying no signal from RRU. When I go into Rudder centering, the display indicator shows the rudder moving and can center the rudder at 2 degrees. I lock in the setting but when I go to do sea trial and try to set it, its stuck on 28 degrees starboard. The indicator does not move when I move the rudder and it fails the test. I'm beginning to believe the processor is bad. Any thoughts?

 

[Johnny Electron]

If the RRU tests good then yes, the processors should be evaluated.

 

[musicmanjer]

Hey Johnny,
Ok, im ready to rip all my hair out.
Ive replaced the AP processor and went through the dockside setup. Went through all the steps and when I go to the Rudder Test, it fails. The Rudder sensor alignment shows the rudder moving from port to starboard with 2 degrees being rudder center when I manually move the wheel. I can go to the air bleeding and press arrows port and starboard. The indicator shows fine with respective button pushes.
When I go to do the Rudder test, it initiates but does not show anything on the rudder indicator then fails.
I can initiate the test and hear the motor working and physically see the rudder moving. It goes from center to port, back to center then port, then back to center.
What is shocking is I can go back to the air bleed and press the buttons, and they move the rudder but now reversed port to starboard.
The motor is a two wire reversible 12v motor.
What am I doing wrong??!!

 

[musicmanjer]

If the RRU tests good then yes, the processors should be evaluated.

Johnny,
Both the RRU and the processor have been replaced now. I am going round and round with this.
Dockside setup, I can go to the Air Bleeding function and toggle between port and stbd buttons and watch the indicator go all the way port and all the way stbd by pressing arrows. Therudder is being moved by the pump.
Ive gone through setting up the other items but when I go to Rudder Test and perform it, it fails every time. I see nothing on the indicators of the rudder moving during the test. I can physically see the rudder moving but back and forth between center and port, but it never goes stbd, then fails. The pump is working but it seems during the test it never shows that it is on the indicators.
I really need help with this as we have a 16 hr journey around the island for haul-out next week.
Thank You,

 

[musicmanjer]

Ok, so I contacted Furuno Technical support since I never heard back from anyone her. This is what I have learned by speaking to a real human over the phone:
1) When doing the Rudder Limit settings, you cannot just enter in the values arbitrarily for Port, Starboard and Center, which the software allows you to do. I had found the limits by looking at the Rudder display, written them down then entered them. THIS DOES NOT WORK! When entering in the values, First you must go to Air Bleed, move the rudder to max Port, log the value on the display. I did it this way as the display would sometimes not show the values accurately on any other setting, so I used "Air Bleed". ("Rudder Limit" did not have a display to show me where the rudder was, this is why I went to "Air Bleed"). Do not move the rudder at this time,
2) Go out of "Air Bleeding" mode, then go into "Rudder Limit", Find Port Setting (0-50) then enter in your value using control knob (mine was 42).
3) Go out of that, go back in to "Air Bleeding" and move rudder to max Starboard position. Log the value shown on display.
4) Go out of "Air bleed" mode, back in to "Rudder Limit", find Starboard setting (0-50) Enter in your value from display with control knob (Mine was 37).
5) Go out of that, go to "Air Bleed" and move the rudder to your center position (Mine was 1 deg Stbd). Go back to "Rudder Limit" and set the Rudder Center, Push enter with control knob to log its value. Exit the "Rudder Limit" settings.

Once this is done, the computer stores the settings given by the rudder sensor by recognizing the resistance in Ohms that the RRU reads at Port, Starboard and Center. Now, my software on the FAP-5001 is older and different than what the manual shows on section 3.2.7 "Adjusting Rudder Reference Unit" as it is described differently on my display showing "Rudder Limit Settings" vs what is written. This was a problem big when interpreting the instructions and it looks much different on my screen display.

6) Go to Rudder Test. Initiate test making sure rudder is centered before initiating. Run the test and the rudder should pass the test. Mine finally did.

Ron at Furuno Support in Washington really saved me this time by explaining how the processor reads and stores the settings. Thank you for providing this service for folks and fishermen like me who can't just ditch their old equipment and get new stuff. I had spent hours trying to get the settings to work. Hopefully this clarifies for someone else who had this issue.

 

[Johnny Electron]

Glad Ron got you on track. I was out of pocked the last couple of weeks. The setup is very important and if not turning the (Helm) RRU when establishing the hard over locations it won't function correctly. It needs to be turned to store the exact location of the RRU each direction. The number being dialed in is not nearly as important as being hard over when storing the value. Glad to hear everything got sorted out. The techs on the phones are very good.