Instrument Panel help needed

[McGillicuddy]

Follow the wires. One by one. Track them and document them on a piece of paper, what color? where do they lead to? Positive or negative? What are the wire colors associated with your unknowns? In all likelyhood they're pre-wired from the power source to a breaker/fuse to a switch. They may be open waiting for you to wire a fish finder or gps or a stereo to them. Sure you don't have breakers instead of fuses? The little rubber buttons sound like reset buttons for circuit breakers. In the darkness, press the reset for the instrument panel (3, I think you said), turn main power switch on, turn the ignition on and see if it lights up.
Go to the library and check out Powerboaters Guide to Electrical Systems by Ed Sherman, and Nigel Calder's book Boatowners Mechanical and Electrical Manual. They are also available online for about $30 and worth every penny. They even have standards charts for wire colors. Here's a freebie:
http://images.google.com/imgres?imgurl=http://www.screamandfly.com/home/hull_tech/wiring_6.6.2004/images/007.jpg&imgrefurl=http://www.screamandfly.com/home/hull_tech/wiring_6.6.2004/wiring_1.htm&h=600&w=800&sz=93&hl=en&start=13&tbni d=hyjcTixMgBD2OM:&tbnh=107&tbnw=143&prev=/images%3Fq%3Dboat%2Bwiring%26gbv%3D2%26svnum%3D10% 26hl%3Den%26client%3Dfirefox-a%26rls%3Dorg.mozilla:en-USfficial%26sa%3DG
Sounds like you already have a good system and you just need to get a better grasp on it. Good luck.