B & G Network auto pilot fault.

[travellerw]

Originally Posted by Symphony

I am also thinking of digital things in general, especially software or comms protocols. when something is in an error state all bets are off!

Since no developer could possibly determine every failure mode, they do the best to write descriptive errors. Sometimes a failure occurs and the error message doesn't really match the failure mode. However, the error should provide a good hint at where to start looking.

I know nothing about older B&G autopilots, but in this case I would start checking connections between the RRU and computer for corrosion. As with all troubleshooting, you start with the simple stuff first. Then get a multimeter and measure the voltage coming out of the RRU. The installation manual has the following text:

"When the rudder is moved from hard-over port to hard-over starboard
the RRU arm should swing through a minimum of 90º, this will ensure
that there is sufficient voltage output to the autopilot. Measure the
voltage difference between the green and blue wires of the RRU,
there should be a minimum of 1 volt change from hard over to hard
over. N.B. If there is less than 1 Volt change the Pilot will not
commission. "

There are more troubleshooting hints on page 16 found here.
http://www.bandg.com/Documents/produ...epslanguage=de

[captain mitch]

My experience with B&G is that it is VERY sensitive to clean good connections between units.
You should first look carefully at the rudder position indicator (should be connector near the ram) then clean all the connections and check voltage at the unit.

[Chuck Hawley]

I know this is substantially different that the other proposed solutions, but I solved some particularly vexing B&G Autopilot problems with a very different solution.

Actually, it was a SIMRAD autopilot controller and the linear hydraulic actuator. But the companies are both under Navico, so it becomes difficult to tell what is B&G and what is Simrad. And most of my other gear is from B&G.

My problem was that hydraulic linear actuator had leaked hydraulic fluid, and it couldn't execute what the course computer was expecting. As a result, I would get all sorts of error messages, but most of the concerned the rudder angle sensor. Since the course computer was saying "starboard!" and the rudder wasn't moving, the software presumed a rudder angle sensor failure.

I found it challenging to find any information on how to refill the hydraulic actuator in any of the Navico/Simrad/B&G documentation, but I ended up buying some hydraulic fluid and filling the reservoir on top of the actuator, then moving the ram back and forth to force out the air bubbles. I did this several times, then got the autopilot to work, and made it go through full cycles. I topped off the reservoir a few times while this was going on. Since then: perfect autopilot performance. It was not necessary to crack any hydraulic lines to bleed the system.

I hope this is helpful.

Chuck Hawley
Alerion Express 38 Yawl, #6 "Surprise"

[colemj]

The OP's system is pre-Navico purchase.

Yes, a drive malfunction would also give the error he has. Besides air in the fluid, or low on fluid, other potential drive problems are worn motor brushes and a bad solenoid.

However, the OP's drive appears to be driving the rudder fine - just not in the way expected.

Hopefully he will return and tell us if he tried any of the suggestions given.

Mark

[YPSILANTI]

Thank you so much to all the very helpful replies. I will work through the solutions when next at the boat. Much appreciated.
Regards
Mike

[s/v Jedi]

Originally Posted by YPSILANTI

Thank you so much to all the very helpful replies. I will work through the solutions when next at the boat. Much appreciated.
Regards
Mike

Mike have you found the problem?

[YPSILANTI]

Greetings,
Yes I did. With the help of this forum, I found that the small ball and sockets on the sensor attached to the rudder quadrant had become worn and had dislodged. I replaced the rod and sockets with a new unit and it is functioning flawlessly.

Thanks so much for enquiring and for all the assistance.

Regards
Mike

[BERSCHERT]

I have been having the same problem, my unit however is a 24 Volt on my British Built Bowman 48. In communicating with Myles at Myles El;ectric, a very knowledgeable individual, he in turn has been on the phone with england and started with this:
Rotary Rudder Reference Unit setup

1.) Ensure the cable coming out of the RRU is opposite the arm when at amid-ships

2.) At amid-ships the angle between the arm and the drag link should be 90 degrees as should the angle between the draglink and the virtual rudder tiller.

3.) Measure the voltage on the Blue and Brown wires. It should be about 5 volts DC. Measure Blue to Green, it should be half the previous reading 2.5 volts.

4.) While monitoring this voltage move the helm fully one direction to the end stop, notice the voltage changes about half a volt. Note the voltage and move the helm to the other rudder end stop and note the total voltage change is more than one volt and that it did not jump or go to zero at any time. The change must be greater than 1 volt otherwise the commissioning will fail.

5.) At the same time you are turning helm to helm make sure the draglink is long enough that it does not straighten out with the arm, and not so long that it can become double jointed. Make any adjustments and recheck everything.

6.) When you are satisfied you have it right recommission the pilot and you should be ready for sea trial.

Well I did that and my error RDR DRV was still with me, I am presently removing the Linear Activator (the shock absorber looking thing that moves the rudder and seeing if the hydraulic oil leaked out, but IO am too fat to fit beneath the area where it is! Hahaha, so I have a very small friend in there trying to get it out!

Then I got this: It is a way to add fluid to the hydraulic ram, see attachment, I can hear the motor of the linear actuator run, but the ram does not turn the wheel quadrant, so assume oil, which I can not see any around the unit, has leaked, so even that is highly doubtful that it did leak, hence no evidence, so I am kinds screwed too!!
Koozapeers@yahoo.com

[Exile]

Mine in fact leaked. Same deal -- could hear the motor running but no movement from the hydraulic ram. Called Myles and he advised taking it to a good hydraulics shop to replace the seals and refill/bleed with new oil. That's where it is now.

Are you sure yours hasn't leaked oil? I ask because it wasn't readily apparent on mine, at least until I ran my hand underneath where the rod exits the housing. The stuff seems to be almost transparent. Myles advised, btw, that the oil can be replaced with standard hydraulic jack oil available from Ace Hardware stores.

[BERSCHERT]

I am taking it out tonight and bringing it somewhere to have it checked, what type of shop did you find and how can I research one?

[Exile]

Originally Posted by BERSCHERT

I am taking it out tonight and bringing it somewhere to have it checked, what type of shop did you find and how can I research one?

I'm in Norfolk, VA so a specialty hydraulics shop was easy to find. The yard where I'm at has some heavy equipment like lifts & cranes so I just asked the owner for a recommendation. Turns out this shop also does work for US Navy ships.

If you strike out on a shop in your area, B&G put out an instruction sheet at one point (pre-Navico) on how to bleed. I have it printed out and keep it onboard but I'm not at my boat right now. If I find an e-copy saved on my computer I'll post. If not, I may have very well found it from another CF thread so you may want to do a search. It looks doable but there's a kit which B&G used to sell to facilitate the bleeding process. Unfortunately, Myles says it's no longer available.

Btw, Myles did advise that a small amount of leakage from non-use is to be expected, and usually the seals will expand & restore themselves after the AP is put back into use. It sounds like in both our cases, however, they were beyond the point of no return. I'm hopeful the hydraulic shop can resolve it. If so, I plan on purchasing from them a spare set of seals, extra fluid, and whatever tubing may be needed to get fluid into the ram.

[BERSCHERT]

Is this the file that instructs you how to bled the actR3800 (1).pdfuator?

[Exile]

Originally Posted by BERSCHERT

Is this the file that instructs you how to bled the actAttachment 177502uator?

Looks familiar. Here's what I have:

[BERSCHERT]

Thanks I will let you know how it works out!! The Attachments are a great help!

[BERSCHERT]

I got my blue T-2 -24 volt Linear Actuator out last night, and It was crazy tight in there, I am trying to find a shop to rebuild the unit but kep striking out, seems so far I have been from Florida, to Rhode Island with no luck, do you have the number of the shop your unit is in, shipping it to Norfolk from Baltimore doesn't seem so bad