I have a 1990 Gulfstream 232 and am suffering a confusing day. I have twin 2000 Yamaha 150 HPDI motors. I have two batteries and two battery switches. The batteries are 24 volt, but the motors and stereo gear are 12 volt. I have an electronics background, so I understand the difference. Is this a factory setup or a mod or am I just crazy? I've owned the boat for years and have changed batteries before but for some reason I'm just noticing this. This is embarrassing but I gotta know.