As I already mentioned earlier as the preliminary qualification for all my subsequent coments, but will now emphasize:
jimh wrote:If the gauges are NMEA-2000 devices...
The wiring harness you have now revealed in your illustration (Fig. 2) above looks more like a an old, obsolete harness--but probably is for NMEA-2000 components, just with very out-of-date connectors
Read:
I-Command Installation and User Guidehttp://continuouswave.com/whaler/reference/NMEA2000/I-CommandInstallation.pdfRefer to the diagram "COMPONENT CHART" on Page 10. Refer to item with CALLOUT 12, called the "TACH SPEEDO HARNESS #763358." That is probably the cable you have on hand.
This cable appears to perhaps be a NMEA-2000 cable. You connect the two gauges, TACH and SPEEDO, to the two appropriate connectors on the harness.
There are two other connectors on the harness. One connector will be for connecting to a NMEA-2000 network (as shown by going to a HUB device). The other is for extending the network to more I-COMMAND gauges, if any, that are close to the TACH and SPEED gauges.
You MAY be able to use this with a modern NMEA-2000 network with DeviceNET connectors. The easiest way to do this will be to cut off one of the network connectors on the harness, and wire it to a DeviceNET connector.
If I were trying this, I would look to see if the two network connectors on the harness mate with each other. If they do, then one connector will have pins and the other will have sockets. I would simply cut off the connector with the sockets from the harness but leaving enough wire attached at the connector be be useful for making a splice to another cable, Then insulate the wires on the harness. Then I would get a DeviceNET cable. I would cut it in to, and then wire the DeviceNET cable to the connector I cut off the harness, making an ADAPTOR. Then the connector on the harness will mate to the harness-style connector on the adaptor.
CAUTION: it looks like there is a 12-Volt power connection as part of the obsolete cable you have. I have no idea how the power is wired with this harness. Read the comments in the article I linked to (above) about NMEA-2000 network power.
ASIDE: if providing an image of a wiring harness with multiple connectors, the arrangement of the connectors in the harness would be more clearly seen if the cable were not photographed while in a tangle.