Learning the hardway
Many of us have bought boats without the original manuals and even with the manuals, many are generic, not specific to your boat. Case in point: My batteries kept going dead. They both checked great with a load tester but as they were 2 years old, I changed the cranking battery. Next time I went to start the boat, both were dead. I kept blaming the CO monitor. A year later after I installed a 8D commercial truck battery as a house battery. A week later i went into the cabin and heard something running. Yep, what I thought was a 120 V refrigerator was actually a dual voltage system with the DC wired direct to battery switch. The refrigerator had been running my batteries down for a year. All I had to do was turn the thermostat off in the fridge. I had only heard it run before when on shore power. I wished I would of found the Maxum Owners Forum when I bought the boat.
Life's too short to drink warm beer!