Bizarre house battery wiring - help!

[boatingbob]

Hi All!

I have a 1995 Carver 390 CPMY that my wife and I enjoy very much, but the way they (Carver?) wired in the House bank is making me crazy! As far as I can see, the house bank goes to the inverter, and powers the 110v outlets and the microwave. The 12v lights, instruments, and refrigerator (when not on shore power) are powered by the starting batteries (!).

We can all agree this is a weird system. I don't think the house battery/inverter installation is a DIY affair, 'coz it looks too neat. The starting batteries are currently kept charged by a built-in charger mounted on the aft engine compartment bulkhead, and the house batteries are charged by the inverter when the boat is connected to shore power.

What we can't find is any switching that allows the house bank to run the 12v circuits in the boat! Under the companionway stairs is the switch that lets me chose starting battery 1/2/both, and under the dinette area is the inverter and a switch (on/off) that allows house battery juice to flow to the inverter.

This hasn't been an issue up to this point, 'coz anywhere we go we hook up to shore power, but any time on the hook, and the fridge will run down my starting batteries in no time! A friend suggested there must be a switch somewhere that links the house bank to the 12v circuits, but we simply haven't found it.

Does anybody have any clues here??? Thanks!

[bud37]

I have an idea that may have been added......do you still have the owners manual ?, if not here is a link to it with an electrical diagram and explanations...you may have this but here it is anyways......http://www.carveryachts.com/media/4083/ ... _95_v1.pdf

[boatingbob]

Thanks! I'm starting to think that the inverter and even the genset (Kohler) were aftermarket jobs. Whereas a lot of 390CPMYs mount the genset longitudinally over the stringers, mine is mounted in front of the port engine. This puts it right over the port raw water intake, which will make replacing the hose a challenge.

I still have a hard time believing whoever put the house batteries/inverter in wouldn't have incorporated some way for the house batteries to tie into the 12v system. It just seems like such a waste of time (and power). Still when I bought the boat, the inverter didn't work. I later found out it was because whoever put in the 4 - 6v house batteries literally put the two middle ones in backwards!!! After I reversed them, the inverter powered my outlets and microwave just great!

I get the impression the previous owners never spent any time on the hook...

[Viper]

Are you sure the battery selector switch doesn't control the source (battery bank) that your house loads work off? That's part of why it's there. How have you come to the conclusion that by adjusting the position of this switch does nothing to draw house loads from the house bank? I can't see it being intentionally hooked up the way you describe unless someone accidentally crossed some wires or didn't know what they were doing.