240 1999 battery goes flatver night

[Colin lighten]

Hi , my battery goes flat. I have two new batteries and the volt meter goes up and down when revving, so alternator is ok. But the battery can go flat overnight, I switch to one battery , turn fridge off and don't use the lights. Funny thing is that when I Turn the water power switch on, I can some times hear a slight motor Noise,even though I am not running the water, when the louder water pump notice is heard. When engine is running, if I turn on the water power switch you can see the volt meter drop half a volt, its like turning the light on in a car. Any thoughts?

 

[JimG]

I'd say you have a battery that's at End-of-Life (EOL).

As far as the water pump... you probably have a slight leak somewhere making the pump cycle.

 

[skibum]

Hi , my battery goes flat. I have two new batteries and the volt meter goes up and down when revving, so alternator is ok. But the battery can go flat overnight, I switch to one battery , turn fridge off and don't use the lights. Funny thing is that when I Turn the water power switch on, I can some times hear a slight motor Noise,even though I am not running the water, when the louder water pump notice is heard. When engine is running, if I turn on the water power switch you can see the volt meter drop half a volt, its like turning the light on in a car. Any thoughts?

Do you have any water in your fresh water tank? If not, the pump will run all night if that water pump breaker is turned on. There is a pressure switch that will stop the pump from running, but if there is no water in the system, it can't build up water pressure it needs to activate the switch and shut off the pump.

If you have any water leaks in the system, the pump might turn on every once in a while to pressurize the lines.

What do you mean by "louder pump"? Do you have more than one pump running at a time?

Oh, and a small voltage drop is fine while the pump is running.