I was familiarinzing myself with the new 380 yesterday and with shore power plugged in (AC 120) I turned on the tv/vcr switch on the panel (this boat does not nor ever had a tv) when i turned on the switch i get motor running somewhere in the upper shower/under dash area. Anyone have any idea what that switch could be wired to? i spoke with previous owner (who is original owner and says never any wiring done and never a tv) and he has no idea.

Could it be your shower sump direct wired? Does it have a vacuflush?

If you think it is behind the dash, remove the gauges and take a peek....super easy.

Does it have a blower/vent in the shower try turning that switch on in the head and see if it is the same sound. Or as Pwraddr says may be shower sump which would be at the base of the last step as you come into the cabin.