I recommend you contact Boston Whaler customer service for advice on how to access any cable routing paths that extend into the interior of the hard top of your 255 CONQUEST.
Also, you could explore the extensive documentation and drawings of the boat available from WHALER.COM. See
https://www.bostonwhaler.com/boat-ownership/resources/A drawing does show some details of the hard top, but I don't see the cable path clearly indicated. Cf.:
http://bostonwhaler.com.s3.amazonaws.co ... t-2010.pdfIt would be typical for Boston Whaler to leave a pull cord in any cable path. Perhaps if you remove the breaker panel overhead in the hard top you will find a pull cord which can be used to pull in more wiring.