It connects to a wiring harness in the helm under the storage box. There's a fuse block in there and the wireing harness connects to that. The fuse box also has a relay built into it that I believe is for the auto bilge circuit but I'm not 100% certain on that yet.
I'm still digging into this as well since my auto bilge sensor doesn't work. The wires have continuity from the sensor plug in the engine bay to the fuse block. The bilge works with the manual switch but the auto circuit does not. I can bridge the connection on the harness as well but this does not activate the bilge either. So I'm thinking that relay is bad.