The bilge pump sits in a low spot in the hull just in front of and in between the engines, next to the fuel tank, or at least it does on my 95. You can test the pump itself by tracing the wires back up and giving them 12VDC. I’ve seen a lot of automatic pumps that were direct wired rather than run through the factory switch, so the first thing you should do is trace the leads coming from the pump and see where they run.