NMEA wire connections for Furuno devices

[Lahara]

I'm seeking to transfer NMEA information from a below-decks Furuno GP32 GPS to a cockpit mounted Furuno LS4100 depth sounder.

I'm hoping some of the sages on this forum more knowledgeable in these matters can assist.

One might think that information on connecting devices from the same manufacturer would be easy to find but I've had considerable difficulty despite extensive web searching and close study of circuit diagrams in finding out stuff that doesn't assume an electronics degree.

In regard to wire colours, what I have ascertained is that the GPS white (TX+) and GPS blue (TX-) are to be connected to the sounder yellow (RX+) and sounder green (RX-).

My query is which GPS colour to which sounder colour?

Two plus or to minus, that is the question.

I realise only low voltages are involved and I'll have a 50 per cent chance of being right first time by using trial and error but I'm worried a wrong connection will cause damage so I'd like to do it right first time.

 

[alan]

White to Yellow and blue to green.

 

[Lahara]

Thanks Alan. I had suspected it was this (that is, + to + and - to -) as this is the connection used by the GPS and my VHF radio, but which is another brand. Incidentally, do you know if connecting them up the other way (that is, + to -) would have caused any damage.

And of course, what I find surprising is that such a simple thing to ascertain is so hard to find on the Web.

Thanks again.

 

[alan]

According to the NMEA standard, equipment should be designed to be able to cope with connecting them the wrong way round. Just make sure you don't mix up the power lead (+12v) with the NMEA wires .... that could damage something.