Main connector rotten by salt

hello there
i'm  on a small island with no possibility of repairs

1- the connector at the back of the GPS got completely broken by salt

2- i oppened the GPS + got it working by making direct connection to battery

but : i don't know to wich cable INSIDE the GPS i need to connect the cables coming from the SOUNDER

>>>> my question <<<<

WICH of the 13 cables INSIDE the GPS
(two series of cables)

serie 1 :
-yellow
-red
-blue
-bare    (coated together)
-black  (coated together)
-white  (coated together)

serie 2 :
-red       (wich i connected to battery +)
-black    (wich i connected to battery - )
-blue     (i think NMEA but i don't need it and even know what this is)
-brown   (i think NMEA but i don't need it and even know what this is)
-white    (i think no connection)
-green   (i think no connection)
-yellow  (i think ALARM, but i don't need that)

GOES TO
the transducer connections         4 = positive (depth)
                                                 5 = negative (depth) / shield

i admit allredy have asked the makers
but they don't want to tell

thanks for your eventual help
Helmut