Speedo sensor don't work

[Alexis]

Speedo sensor don\'t work

Hello there,

I meant to send this question to "Ask the experts", but was diverted to this forum. That's probably what PBO think you are (experts, that is).
Problem: I have a speed/log(and it seems sea temperature) sensor unit (ST550) linked to a B&G Hydra 330 central unit. The paddle wheel spins totally freely, and is installed the right way around. Whatever the speed and distance I sail, the display displays(!) "00.00 knots". I have redone the connections on the central unit to no avail. How can I check if the sensor unit is to blame ?

<hr width=100% size=1>

 

[Colin_S]

Re: Speedo sensor don\'t work

I had a problem with a speed senson on a PWC some years back. It had a paddle wheel and 3 wires to the unit. The method of checking was to put a volt meter in the 12v range across 2 of the wires, power up the unit and then slowly rotate the wheel. The voltage would vary between 5.5 and 8.5v dc. The 2 wires were not any 2 but a select pair identified by colour from a shop manual.

That may or may not help you of course but, if it's got 2 wires I would try breaking into the wiring either by unplugging a connector and use a couple of 'jumper' leads to reconnect it with some insulation exposed to put a meter on or use a couple of fine needles to pierce the insulation on the loom and put a meter on them to check it. Make sure meter's set to volts!

Sorry this is probably not much help but I expect someone who knows the propper way of doing it will pipe up soon.

<hr width=100% size=1>

 

[Guest]

Re: Speedo sensor don\'t work

Assuming all else is correct ... electric supply, connections etc. etc. - paddle wheels have a small magnet in one of the paddle blades ... this when passing the reed iin the wheel housing causes a pulse. The number of pulses gives the speed of the wheel and so the speed of the boat.

It could be that you have lost the small magnet in the paddle. This can happen when overzealous yard guys high-pressure hose of hulls .... a little game some oplay is to see how fast they can get the wheel up to with the hose .... the magnet then flies out of its little seat.

Check the paddle and see if there is a small empty hole in one face ? It may be possible to replace with a magnet chip - but its finding a supplier of them !
It may be possible to change the paddle itself - normally held in place by a thin stainless steel pin through the plastic body .....

If the boat is out of water ..... you could switch on and with a low normal hose squirt a jet at it and have another read the display after checking everything you can ..... ?

<hr width=100% size=1>Nigel ... and of course Yahoo groups :
http://groups.yahoo.com/group/gps-navigator/