high-pitched alarm on a 1991 Ranger 361V

[silrleveret]

I have a 1991 Ranger 361V parked outside on the trailer. I heard a high-pitched sound, looked out and saw the instrument panel was lit up on the boat. Pushed the switch on one of the aerators and the sound stopped but the panel was still lit. Had a 3 amp fuse for the electronics blow over the weekend. Pulled it out and the lights went off. Any ideas what the problem is?