I’m in the throws of installing a new autopilot and radar on our new-to-us J/109.
As part of that I cleaned up the dogs breakfast of a NMEA 2000 network the boat came with to make it both easier to trouble shoot and hopefully more reliable, particularly since this new kit required adding quite a few network devices.
When all was said and done I ended up with a couple of old network cables that I had replaced because they looked a bit manky (another deeply technical word).
I was about to throw the old cables away when it struck me that by cutting them both in half and stripping the ends I would end up with a zero cost NMEA 2000 trouble shooting kit for use with a voltmeter.
I also added a male to female connector I had left over to the kit. Useful to substitute for a T connector to get a suspected device or drop out of the mix, but still keep the backbone connected.
The kit proved invaluable while hunting down a brand new power-T with an open circuit on one of the network lines.
And here’s a good primer on trouble shooting NMEA 2000.
By the way, I don’t think most of us need an expensive N2K meter, particular since a lot of devices, such as plotters, have trouble shooting screens which will let us check for excess error packets and the like—dig deep in the menus and check regularly to catch potential intermittent problems early.
More thoughts on NMEA 2000: