Gremlins in instruments

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windward1
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Posts: 146
Gremlins in instruments

I have a pod of Raymarine st 50 instruments as part of the sea talk package that came with the boat. Last year and again this year, the wind indicator only works occasionally. It worked fine the end of last season and only the first couple of days this year. It shows the correct wind direction, but "0" wind speed when in the slip. I have checked the voltage at the bottom of the mast on each wire all of which are according to specs and the connections are good. I think this tells me the transducer at the mast head is working fine. Someone else thinks that because the instrument is sometimes correct it must be ok.

Also the knot meter only shows 1 to 3 knots even if I am going 6 and the water temperature shows to be 104 degrees. When moving on the water the knot meter speed shows up as wind speed on the wind instrument. The depth and auto work fine. Any suggestions are welcomed. Electronics was never my forte

Richard
1994 C36 Tall Rig M1.5
Waukegan Harbor
Lake Michigan

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baysailor2000
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Posts: 218

I have similar problems - but not as often as yours. I have not been able to corect mine yet. I suspect that I will not be able to resolve mine. All the display data line are chained toghether so it is possible that sometimes two data show up at the same time and they produce interesting results. In my case I sometimes get three dashes ( - - - ) for depth, then it works again for no reason at all. And yes I see the kind of data on a display that belongs to so me other display.
If yours is very often - I would disconncet one transducer at a time and see if that corrects the problem. it may also be a corroded contacts on the data line producing "noise" that corrups the data.

Haro Bayandorian, 1999 C36 MKII, Sail La Vie #1787, M35B,
Coyote Point, San Mateo, CA.

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TomSoko
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Posts: 978

Richard,
I can't help you with the cross-pollination of data, but if your water temp is reading 104 all the time, I think the speed/temp transducer is NG. I replaced mine last year when that happened, and it fixed the problem. They are made by a company called Airmar, and cost about $100.

Tom Sokoloski
C36/375IA Past Commodore
Noank, CT

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plaineolde
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Posts: 753

my knotmeter transducer reads fine for speed, but has been all over the map for temperature for many years. I've resorted to the foot test; if I stick my foot in the water for 30 seconds and it doesn't get numb to my knee, it's warm enough to swim, otherwise, too cold. Not as accurate, but all I really need to know:)

Gary and Cathy Price
1997 C36 Mk II Tall Rig/Wing Keel Imagine...
Hull # 1617
Worton Creek, Md.
Northern Chesapeake Bay

deltahans
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Joined: 10/20/11
Posts: 15

This is pretty weird. Last week, the wind speed worked fine, but yesterday it was doing the same thing described here - direction is fine, but boat speed is indicated, not wind. I hope someone has a clue how to fix it. Thanks, DH

David Hanson
-Watercolor-
1993 C-36 MKI #1244
Stockton CA

windward1
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Posts: 146

Tom, I think you are correct about having to get a new knot meter transducer. I did read somewhere that if the temperature is not working there is water intrusion in the transducer and it must be replaced. Gary, I also use the foot method for testing the water and don't even think about jumping into Lake Michigan until late July.

The knot meter must "talk" to the wind instrument in order to calculate the true/apparent wind minus the boat speed. There is power to the wind and the direction works. Maybe the problem is the wire transmitting the speed between the mast and the instrument. I am just rambling here searching for an answer. Thanks for the feedback.

Richard
1994 C36 Tall Rig M1.5
Waukegan Harbor
Lake Michigan

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Steve Frost
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Posts: 788

Suns spots, solar flares. It was on the Mayan calendar.

Cepheus dream
C36 MK I # 825
MK I Tech Editor No Mas

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HowLin
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Posts: 355

[QUOTE=Steve Frost;13171]Suns spots, solar flares. It was on the Mayan calendar.[/QUOTE]

:eek: Yikes! That explains my last 2 weeks...

---- Howard & Linda Matwick ----

--- S/V "Silhouette" - Nanaimo, BC ----

--- 1999  C36 MkII  #1776 M35BC ---

windward1
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Joined: 9/18/09
Posts: 146

I may have found the solution for the wind speed. I went out today and still had no wind speed-also there was no wind but there were flies and horse flies. Upon returning to my slip I took the instrument pod apart and jiggled all of the wires, especially the small colored wires plugged into the auto pilot. I think the yellow wire is wind speed. In any event the wind speed now works. Time will tell if that was the faulty connection.

Richard
1994 C36 Tall Rig M1.5
Waukegan Harbor
Lake Michigan

windward1
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Posts: 146

This was not the solution. Today wind speed "0" and direction accurate. I opened the pod and disconnected and reconnected all of the connections with no change. I am out of ideas.

Richard
1994 C36 Tall Rig M1.5
Waukegan Harbor
Lake Michigan

Last Toy
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Posts: 28

My wind indicator has been reading wind direction both normally and in reverse. Finally called techican, they are sending the unit to Raymarine for testing.

Barry Thorpe
Miami, Florida
2004 c-36 MKII M35B
Last Toy #2187

windward1
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Joined: 9/18/09
Posts: 146

Believe problem with wind speed resolved. My slip neighbor,a former medical equipment service tech, stated the most common error on electronics is a poor ground connection. The ground might look connected, but if it is not tight problems occur. I found I had a loose twisted connection on the ground wire at the bottom of the mast; redid the connection and the speed is working. Now I have to figure out the knotmeter so I get an accurate apparent wind.

Richard
1994 C36 Tall Rig M1.5
Waukegan Harbor
Lake Michigan

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