I have a Furuno 1715 radar, Furuno GP32 GPS, Icom 504 radio and would like to interface them with my BRP I-Command gages, looking for which cables from each unit to the NMEA system of the gauges, and a wiring diagram Thanks!
I would recommend adding a NMEA 2000 GPS for your BRP I-Command gages. These digital gauges are NMEA-2000 standard devices and will not directly interface with the NMEA 0183 devices without a proper interface. You would also have the problem of having too many listeners on your NMEA 0183 output of your GP32. The current (mA) pulled by the 1715 and the VHF radio would be the max. You could not risk placing a NMEA converter (0183 to 2000) on your GPS output without risking the port being damaged. Rather than buying both a NMEA expander, and a NMEA converter, it would be easier and less complex to add a NMEA 2000 GPS sensor (like the Furuno GP330B or the GP33) to your NMEA 2000 network, supporting your digital gages. To support your 1715 and VHF from the GP32, take the White (+) and Blue (-) wires from the GP32 cable (provided) and wire it to the 1715 (Optional NMEA cable 000-154-028) Yellow (+) and Green (-) and the ICOM 504 VHF NMEA input, Red (Inner core) (+) and the Red (outer shield wire) (-). The GP32 can drive both of these listeners from the White and Blue output wires. It would look like this:
....................................YELLOW (+) 1715 INPUT
GP32 White (+) output ----<
....................................RED (+) Inner Core ICOM 504 INPUT