I just purchased a used 2000 Monterey 240 EX deck boat and a week after i have it , it does not have enough power in the batteries to start it, previous owners say batteries are good , not that old and say that must be auto bidge pump killing it , boat is on trailer in driveway with no rain and no water on driveway so dont believe the pump comes on , also i had switched the battery switch to off . Any other ideas as to what may draw power with switch off. I plan on pulling batteries to load test them to be sure and will have dealer check charging system but any suggestions what could be draining power with switch off would help