More heading data problems

[Pblais]

That's interesting -- does your bad course computer also give you wacky heading information at your plotter?

Nope it just hangs the autopilot but comes back. The data never gets there. The computer is in one half and the wire harness is in a second and they join on a DB 25 connector. I had the connector resoldered on both sides but the connector itself is bad. My buddy John is an old timer that actually can fix this stuff (radios too) but his health is not good any more. He has been doing auto pilots since they were invented. I learned a lot of the easy stuff from him.

Do you happen to know whether the newer course computers are compatible with the older networks?

Course computers need to be compatible with the control head and my computer is out of production (ST7000) but a new one will work with the old control head. The price jumps around and no one stocks them off season so they can be tricky to get. Raymarine can tell you what computers can be replaced with what heads. You can buy the core pack sometimes cheaper than just the computer. It adds the rudder indicator and the fluxgate. The rudder inicators are easy to trouble shoot as they are just a calibrated rheostat so you measure the voltage at the computer. They are known to go bad too. A multimeter should show a smooth voltage range from hard over to hard over. You can get dead spots (not good). Poor location of the fluxgate is a most common problem.

[Dockhead]

Originally Posted by goboatingnow

Id replace a few of the seatalk cables first before commiting to 3K. !

DAve

That's good advice!

I guess that EVERYTHING would be explained by a bad Seatalk connection between the course computer and the RL80CRC+. The autopilot gets its heading data directly from the course computer, right? So such a bad connection would not affect the autopilot. While making the plotter go crazy. That's worth a shot I guess.

Does anyone know whether Raymarine will check a Smartpilot S3 course computer for faults, if I send it in to them? I'm concerned about what Paul said -- that they have known soldering issues.

I notice that Raymarine sell a separate gyro unit -- the E12101 (Raymarine Marine Electronics - Gyroplus II External Rate Gyro Processor) which will apparently convert my non-gyro course computer to a gyro one. A good bit cheaper than changing the whole course computer. Maybe this would be a useful upgrade in case the course computer itself can be confirmed to be functioning correctly.

[Dockhead]

Furthermore, the pilot steered me flawlessly across the English Channel six times last year. I calculated tidal offsets, calculated the magnetic heading, programmed that heading into the ST7000+, and made landfall 60 to 80 miles later within a cable or two of where I intended, which I thought was quite remarkable.

So I guess the course computer has to be ok. I will concentrate on the cables, and maybe try to buy that gyro upgrade.

[1stopyacht]

Radar settings are either magnetic or true. You need to go to your settings to see what you have and switch to the other to see if it will correct the problem. (if magnetic, switch to true, if true switch to magnetic). If that doesn't help, then you might want to consider the upgrade.

[Dockhead]

Originally Posted by 1stopyacht

Radar settings are either magnetic or true. You need to go to your settings to see what you have and switch to the other to see if it will correct the problem. (if magnetic, switch to true, if true switch to magnetic). If that doesn't help, then you might want to consider the upgrade.

Well, I don't need to go to my settings -- I use magnetic everywhere so that everything corresponds with my compass.

I have used true and the problem was the same.

I replaced the fluxgate compass and swung it properly after installation. It seems to be fine, and the course computer seems to be fine, based on good performance of the pilot.

[Pblais]

Does anyone know whether Raymarine will check a Smartpilot S3 course computer for faults, if I send it in to them?

I don't think they can but you could ask. For the most part you are expected to work with a dealer and they will swap out the parts until they find what needs to be replaced. It means they can stock hot swap parts where you have to buy them and pay restocking fees. No one actually fixes anything and I doubt they have service technicians that will or can do a full factory test. This stuff is all made by contractors. The bench testing gear is expensive. The technicians that can do it cost a lot too. Replacement parts on the shelf cost little and a shipping clerk can handle all the technical details.

Main thing is divide and conquer. You can test the sensors that feed the computer. Note that all data out of the computer is corrected by the computer and retransmitted in a proper format. Nothing else will read the Fluxgate data or the rudder feedback. It needs to be that way so the deviation table adjustments get added in to the result and the rudder converts to degrees and re calibrates based on the drive unit. The course computer just outputs standard stuff based on what it gets in. That can also include waypoint data as well as GPS. It's not like an instrument that just displays signals.

A bad control head can make a mess of things as well. I've never had to trouble shoot a control head.

With all the wires that run around it's easy to have a wiring problem, but of course finding the right one becomes a trick. You can make bridges and test segments one at a time. Unless the wire is really shorted it can be hard to find. Any wire that flops about would be suspect. Being lucky still counts. Be methodical and persistent.

[Dockhead]

Thanks, Paul. That's great advice.

I think I have now figured out that the course computer must be ok. I think I will now replace the Seatalk cable between the S3 computer and the RL80CRC+ and hope for the best.

If that doesn't work then I'll take your advice and try to swap out the course computer -- I suppose it could be outputting good data to the autopilot control head (in a different format?) while it gives faulty data to the RL80CRC+. Seems like a long shot. Then if that doesn't work, I guess I could try making my RL70RC+ at the helm the master, and cutting the RL80 out of the network temporarily -- wire up the course computer directly to the helm. On the off chance that it's a problem with the plotter. If that doesn't work then I guess I have to be "methodical and persistent".

Or be unmethodical and impulsive, throw everything overboard, and start over again with a new system!

[Pblais]

Dockhead I think you get it now It's a little Sherlock Holmes meets high tech engineering. Knowing what it is not leads to something closer to what it is. It works for most things on the boat, except the head. You usually know what it is with a head and that becomes the real problem.

[goboatingnow]

Contrary to what has been said raymarine offer a full and very professional factory repair service at their Portsmouth Uk HQ. They will of course check it out.

While much of the manufacture is contracted out it is designed in Portsmouth and that's where the " smarts" are . Also they have very good phone tech support.

Dave

[Dockhead]

Originally Posted by goboatingnow

Contrary to what has been said raymarine offer a full and very professional factory repair service at their Portsmouth Uk HQ. They will of course check it out.

While much of the manufacture is contracted out it is designed in Portsmouth and that's where the " smarts" are . Also they have very good phone tech support.

Dave

I just drove by their pretty building in Portsmouth just last week. Maybe there's even someone to talk to there? Anyone ever try their tech support?

[Dockhead]

Originally Posted by Pblais

Dockhead I think you get it now It's a little Sherlock Holmes meets high tech engineering. Knowing what it is not leads to something closer to what it is. It works for most things on the boat, except the head. You usually know what it is with a head and that becomes the real problem.

All cruisers should read "Zen and the Art of Motorcycle Maintenance" which is all about this. I read it with great pleasure in my youth and you've now inspired me to read it again.