Raymarine speed / temp sensor

[Boathook]

It has packed up and I just get some dashes on the display. This for boat speed, water temp, etc and also effects the true wind display

Unit is an airmar St 800-p120. As it goes into the raymarine seatalk ng system and all the instruments are devoid of the data a supplier thinks that the water temp has packed up which takes out all the speed data. The unit is not longer made and I'm waiting to hear what the replacement is. Boat was launched yesterday so I don't want to much about changing skin fitting at low water, though where I am tidal range is around 0.5 to 1.5 metres.

I see to remember reading that that the water temp input can be 'fooled' to give data to the system there by allowing everything to work apart from a suspect water temp.

Has anyone and suggestions as to where to look such as links, etc ?

Presently on the boat and struggling with Internet due to lousy mobile signal so searching is difficult !

 

[earlybird]

From Raymarine FAQs here

 

[jdc]

Blowing my own trumpet, you could glance here: ST60 Log not working, post 20 has photos.

 

[CJTurner]

I had a similar issue: the only cure I could find was a complete replacement with an Airmar 810 - an expensive exercise. It is a direct replacement, no need to change the skin fitting. I wished I had kept the old cheap analogue one and used a nmema converter.

 

[earlybird]

Just to expand my earlier post. If the fault is due to the transducer thermistor failure, as frequently happens, the display goes into repeater mode. A resistor across the display brown & white wire terminals should restore normal master instrument operation. Value is not critical but 10kohm is reasonable. I thought the Raymarine link explained this but, (of course), it only tells you to replace the transducer.

 

[CJTurner]

I'm puzzled why the wind speed would be affected. Did you have any more input about that?

Just to expand my earlier post. If the fault is due to the transducer thermistor failure, as frequently happens, the display goes into repeater mode. A resistor across the display brown & white wire terminals should restore normal master instrument operation. Value is not critical but 10kohm is reasonable. I thought the Raymarine link explained this but, (of course), it only tells you to replace the transducer.

 

[earlybird]

I'm puzzled why the wind speed would be affected. Did you have any more input about that?

Without the thermistor connection the function of the display changes. It looks for wind information from the seatalk bus rather than from the transducer; ie repeater mode.

 

[LittleSister]

Just to expand my earlier post. If the fault is due to the transducer thermistor failure, as frequently happens, the display goes into repeater mode. A resistor across the display brown & white wire terminals should restore normal master instrument operation. Value is not critical but 10kohm is reasonable. I thought the Raymarine link explained this but, (of course), it only tells you to replace the transducer.

Blowing my own trumpet, you could glance here: ST60 Log not working, post 20 has photos.

Thanks, Earlybird and JDC, for the timely - for me - reminder of the 'resistor solution'.

I'd found the 'resistor solutlion' described some time ago, quite likely in the old thread that JDC links to, and had even bought a suitable resistor at the time, but 'life' intervened before the job was done, and I lately realised not only did I no longer know where I'd put the resistor, but I couldn't remember what its value should be nor which terminals it should be between (or where I put the piece of paper/niotebook on which I'd carefully noted those things! ). I've now made a new note somewhere 'safe', honest.

You've saved me having to hunt for it all over again, as well as providing the solution to a new cohort of people suffering this common problem.

 

[Boathook]

Thanks all for the replies. I will look into the resistor and order a couple when back home.
I spoke to the dealer (Rowlands Marine Electronics) who supplied the kit and he is certain that it is the sensor rather than the itc-5 causing the problem.

In the mean time I have ordered a new speed / temp sensor that the dealer assures me will fit in the existing skin fitting. I'm just dreading to try and get the new cable through and the agro if the new sensor doesn't fit.

The agro won't be from the dealer as in the past he, plus staff, have been very helpful and with good advice.

 

[Boathook]

I'm puzzled why the wind speed would be affected. Did you have any more input about that?

The true wind speed and direction needs boat speed (log) input to calculate the true wind data. The wind instrument showed the apparent speed and direction as that is what it actually sees.

It's been a learning curve for me !

 

[Boathook]

All back up and running with a new sensor.

Having purchased some resistors last week I tried the one resistor (10k ohm) across the white and brown sea temp terminals on the itc-5 and got a reading of 27C and the log and wind worked correctly using the old log.

New log fitted the through hull fitting ok, but the biggest pain was pulling out the old log sensor wires and pulling through the new ones.

Could have saved myself some money by just using the resistor, but I do like seeing what the sea temperature is and recording it in the log book.

 

[LittleSister]

. . .
Having purchased some resistors last week I tried the one resistor (10k ohm) across the white and brown sea temp terminals on the itc-5 and got a reading of 27C and the log and wind worked correctly using the old log. . .

I like the idea that the fitting of a simple resistor will magically increase my local sea temperature to 27C!

 

[Irish Rover]

All back up and running with a new sensor.

Having purchased some resistors last week I tried the one resistor (10k ohm) across the white and brown sea temp terminals on the itc-5 and got a reading of 27C and the log and wind worked correctly using the old log.

New log fitted the through hull fitting ok, but the biggest pain was pulling out the old log sensor wires and pulling through the new ones.

Could have saved myself some money by just using the resistor, but I do like seeing what the sea temperature is and recording it in the log book.

Was it an Airmar 810 you bought and fitted. If so from where please?

 

[Boathook]

Was it an Airmar 810 you bought and fitted. If so from where please?

It has the model as st900-p120 and e70673 and fits in the self closing skin fitting. Came from Rowlands marine in north Wales. I have found them good and helpful.
Rowlands Marine Electronics | Leading Marine Electronics Dealer