If you have a bilge pump, it should be wired directly to the battery. So, look at the connections to the positive side of the battery, one of them should be the bilge pump, and it will have relatively small gauge wire. Besides that, you will probably have a starter, alternator and distribution connections.
Middle of the boat deck hatch. There should be one for the gas tank sending unit then another for bilge pump or maybe it was one hatch and the pump was on the hull hard to get at. Thats how my 1988 trophy was. Brutal arm scrapper to change.
we should have a drain on the side of the hull somewhere where the water comes out of the bilge if you don’t then you dont have a pump. A lot of old manufactures early in early 80s and 90s did not install pumps