loud siren when I turn on batteries
I recently bought a 30 foot, 1979 seafarer swiftsure. it is in very good condition, the people who owned it before me put lots of money into upgrades and maintenence. I am really happy with it so far.
The problem is, that when I turn either the starter or cabin battery on, a loud, continuous beep plays from a speaker in the dash board under the driver's seat (in the 1st photo). The beeping only turns off once the engine is started. I have been told that this may be a low oil pressure warning, which turns off after the engine starts and pressurizes the oil.
my question is why would the cabin battery be hooked to that speaker in the dash in the first place? shouldn't I be able to have it run my lights and fans while the engine is off? There's a possibility that it was mistakenly wired to that speaker, but who knows.
Any help is appreciated, thank you