DSC radio to GPS interface problems - HELP needed!

[catch 22]

Help! I seem to have tried just about every wire combination to link my radio and GPS together. As yet no luck. I have read about published diagrams being wrong, these are the advice from each products web site. Can anyone tell me for certain which wire on the GPS to connect the 2 from the radio for full DSC data connection – both ways????

Navman 7100 radio wiring:
Connecting VHF 7100, 7200 to a GPS
NMEA OUTPUT + from third party instrument, connect to yellow wire (NMEA IN) on NAVMAN VHF7100
NMEA Output – from third party instrument, connect to Green (NMEA -) on Navman VHF7100

Garmin 178C wiring;
Black – Ground power/data (-)
Blue – Port 1, Data out (tx+)
Brown – Port 1, Data in (rx+)
White – Port 2, Data in (tx+)
Green – Port 2, data out rx+)

Many thanks for any advice given.

[codprawn]

My Navman fuel computer had the colours marked wrong so it is quite possible you have the same problem. Just swap the + and - nmea wires around - only the signal wires - it shouldn't hurt.

[catch 22]

thanks for the advice. i will keep trying. I might be having problems with the common ground, i think.

[jwalker]

Originally Posted by catch 22

Can anyone tell me for certain which wire on the GPS to connect the 2 from the radio for full DSC data connection – both ways????

With only two wires you can't have a two way connection. So, if your info above is complete, the following should be correct.

If your Navman cable colours are correct then; Garmin blue to Navman yellow, Garmin black to Navman green.

You could use Garmin port 2 if you prefer then; Garmin green to Navman yellow, Garmin black to Navman green.

If Codders is correct for your case then the Navman cables will need to be reversed.

[Top banana]

blue out from garmin to yellow in on navman, and the green on the navman to
a common earth such as buz bar.on the 7100 there is no data output from the radio to an external device, only data in to give gps position.

[Top banana]

as jw

[catch 22]

Many thanks to you all, seems clearer now. I will print out your advice and try again this evening. Thanks again.

[catch 22]

All working well after your excellent advice.

Many thanks.