Connecting a Furuno depth sounder to a Raymarine multi

[DaveA]

Sixpence was done on a budget and I had to use whatever I could get hold of, so I ended up with a through hull depth transducer and a Raymarine multi display. The plugs and sockets are not compatible so I've cut off the plug from the Furuno, leaving me with a cable that has a shield, a black wire, and a white wire. The Raymarine has two pins. Would I be correct in assuming that the black and white wires go to the pins and the screen goes to the -ve battery terminal ?