The center conductor of the coax cable is hot or the signal send wire and the shield becomes ground or the signal return wire. To confuse everyone the new Airmar transducers, Raymarine, Garmin, Furuno and many others use Airmar as their transducer supplier, are often three wires, hot, ground and a shield. Any way to convert a transducer plug for a Raytheon to a Furuno? There are the same amount of pins but different configuration. Aug 24, 2020 #2 artodea Lieutenant. Lite User. Joined Jun 28, 2012 Posts 51 ... This site helped with the wiring diagram: Gemeco | Wiring Diagrams Gemeco Marine Accessories. www.gemeco.com Good luck.