I've read all the threads on this issue, but I still have a question and am hoping someone can help.
I have two ST60+ Wind
displays (mounted port and starboard) and suddenly both stopped showing wind
direction and wind speed. On both displays the needle sits at the 12 o'clock position and the speed displays, variously, as "000" or "---".
I felt it highly unlikely to have 2 displays fail together but as one is a master and the other is a slave there is some interdependence, so I switched them over and reassigned the master/slave but this made no difference.
So then I went up the mast
, removed the ST60 wind vane
assembly, cleaned the 5 pin electrical plug
and socket and reinstalled. This got it working correctly again for a few weeks .. on and off. But then same problem returned.
So I figured that maybe the pins on the end of the cable which connects the transducer
to the mast head
base might be corroded so I purchased and installed a new cable in the transducer
(Part A28165, see photo
below). This made no difference.
Today I accessed a junction box at the base of the mast to do some voltage checks according to test procedures supplied by Raymarine
and posted many times on this forum. At the junction box I disconnected the blue, green and yellow wires coming from the ST60+ displays so only the red and shield remained connected through the junction box.
Using the shield as the reference point and measuring the wires which came down the mast:
- the red power wire measured 7.9 volts (which compares favourably with the specified 8 volts +/- 0.25 volts). To me this proved both power and ground wires up/down the mast were intact.
- the yellow wire measurement fluctuated between 2 and 4 volts (compares favourably against specified range of 0 to 5 volts). To me this proved that the wind speed transducer was sending a suitably variable speed signal down the mast.
- the blue wire measurement was fixed on 6.3 volts (exceeds the specified range of 2 to 6 volts). This is the port side directional element, and voltage should vary with wind direction changes.
- the green wire measurement was fixed at 0.7 volts (falls short of the specified range of 2 to 6 volts). This is the starboard side directional element, and voltage should vary with wind direction.
I believe the above results are telling me that the fault is at the top of the mast - with no variation in the voltage on the blue and green wires coming down the mast (even though the vane was observed swinging) the display needle has no reason to move, let alone display a correct wind direction. I believe this calls for a replacement of the small circuit board (Part A28164, see photo
below) in the transducer to restore wind direction.
But the bit I can't make sense of is why the displays don't show any
wind speed given that the voltage sent down the mast in the yellow wire is both variable and within the specified range?
If someone were to confidently assert that an out of range voltage reading from the port and/or starboard wind directional elements means that the wind speed is rendered inoperative
then I would be more confident that replacing the small circuit board will restore both wind direction and wind speed. But just now this doesn't make sense to me - I can't see why the wind speed function would be dependent on the wind direction functioning.
The circuit board costs about $130 and I am capable of replacing it, but I do wonder if this will fix the whole problem, and not just restore wind direction but leave me without wind speed.
Can anyone shed further light on this please?