Raymarine forum

Hi Im trying to get my ST4000 to steer to waypoints etc from my RC425. I have the green wire off the 425 into the NMEA -ve and the white wire into the NMEA +ve
When I try to enter track mode by pressing the Auto key and then +10 and -10 for three seconds, the pilot does not scroll through three displays as indicated, nor does it show any error display. It does appear to adjust course, however I need to double check that. Thank you.

Hi John,

The output from the RC425 is Yellow Data +ve and Brown is data out -ve, you need to use these since you are outputting track information from the RC425 into the ST4000

regards
Derek

I have the wires in their correct place but still cannot get the head unit to produce any scrolling message to verify the interface. The heading gives a 10 degree course change (I think) but I have yet to mount the ram. Its installed.)

Hi John,

So you have rewired the NMEA connection as I advised? The initial connections that were being used were incorrect.

Check the voltage between the two NMEA output wires, you should see some sort of fluctuating voltage between 0 and 5v, so if you see no voltage the NMEA interface in the 425 is failed, if you can see a voltage then the NMEA input to the 4000 is failed.

regards
Derek