B&G speed sensor compatibility

[Streetcar]

I am trying to find a paddlewheel speed sensor which is compatible with my Hercules 690 system. Just wonder is anyone has any experience or knowledge in this area.

The original sonic speed system has finally let go and I want to switch to a paddlewheel option to keep me going. Here's where I've got to:

- The Hercules 690 manual says that the compatible paddlewheel option is 202-00-045.

- The B&G Product Identification Guide says this is discontinued and is replaced by SEN-SPD-HP

- I bought one of these ($$$) and wired it into the Processor unit, spun the wheel and no speed reading on the display...

- The integral temp sensor (part of the speed sensor unit) seems to work when I wire this in as well... but still no speed...

- There are no other issues with the B&G 690 system - everything else works perfectly

Is it likely to be a compatibility issue?
What would cause this and can it be 'corrected'?
Is there a 'more compatible' sensor option? - One person has suggested a 202-00-100 option (or replacement which is produced by A+T Instruments)

[Streetcar]

Just in case anyone else should ever come across this problem, here's the answer:

The SEN-SPD-HP does work on older Hercules units. I had just wired it up wrong (but right according to instructions). Below is the right way. B&G who sold me the sensor didn't have a clue, I had to piece it together from older manuals and various airmar diagrams.

Hercules Terminal -SEN-SPD-HP -Wire
31 -Speed Input/Signal -Green
32
33 -Ground -Black
34 -Sea Temp/Speed power (voltage) -Red & White
35 -Sea Temp Input/Signal -Brown