SO 45 Wind Dept Instruments not working

[sirona]

My boat has been laid up over winter in Spain and so I came out to do annual maintenance, antifouling etc - all electronics are working fine except my instruments showing log speed, wind and auto-helm are not working - they are repeated stb and port side. (ST60+ WInd; ST60+ TriData, ST6002 SmartPilot) As far as I recall, they were turned on with the same switch as the auto-helm, which itself works fine - as I can operate from the remote hand held device.

Can anyone point me in the right direction to check for fuses or some other obvious area. I tried reading through the wiring diagrams on the owners manual but gave up after the 6th wiring diagram! I am reasoning that since all five instruments are "dead" there must be a central issue which I can't figure. Any ideas?

[tedp]

It might be a Seatalk problem as the other instruments probably are fed from the autohelm using the Seatalk cable. The autohelm usually is set up as the first instrument fed from the power switch, and the others are branched from the autohelm control unit. I would have a look at the Seatalk connectors. It might be corrosion.

[sirona]

Thanks TedP for quick response. So although I have wired other SeaTalk units, I thought the units would at least "light up" and albeit no signals from SeaTalk....so I'm confused why there is no sign of any life, suggesting a power supply issue?? Where do I start to look for a central SeaTalk failure?

[tedp]

As far as I know the ST60 instruments use the Seatalk three-pin flat connectors. A seatalk cable carries both the 12V power suppy and the earth (zero volts) link, and the seatalk signals used between the instruments for communication.

Usually the autopilot is directly powered from the instruments power switch (possibly with a power relay handling the actual switching, at least in my SO32 that is the case). The other instruments are wired up using nothing more than the seatalk cables. Only the centre pin on the connectors carries the seatalk data, the outer two handle the power.

If a connector on the autopilot or in the first cable from the pilot to the other instruments is corroded the power to the other instruments may be cut. The cable could be damaged as well.

Depending on the type of autopilot you have, I expect the connectors you'd want to check first are on the back of the control panel of the pilot, or possibly (if you have one of the later autopilots) on a separate computer unit. If these are OK, check the instrument pod where the other end of the Seatalk cable from the autopilot comes in.

I suggest you read up on seatalk connections to the instruments in your autopilot manual or on the Raymarine website.

Here is a link to a simple explanation of the way any instrument is wired up using Seatalk cables. They are just connected up in a chain, with cables going from instrument to instrument:
www.shipnavigator.com/en/seatalk.html

[sirona]

Thank you so much TedP - that is very helpful. I will investigate as you suggest and report back.

[sirona]

Ok got it sorted - found a loose connection which solved the problem! I read the web page on SeaTalk which you recommended, which was very clear. Thanks again for your help.