1984 53’ Hatteras motoryacht, systems monitoring at helm. Bilge light on, no alarm. Boat is in building. Bilges are dry. All 4 high water level switch floats are in down position, made sure were clean. Could this light on no alarm horn condition be indicating a faulty switch? Or something else? Looking for any advice from someone who has maybe run into this before? And if indicating a faulty switch, any recommendations on how to determine which one?