Another Battery Selector Switch question

[Deleted User]

'06 FV 250. Today I discovered that both my battery #1 and battery #2 switch positions only provide power from the starting battery. Only by selecting "both" can I access power from the house battery. So away from shore power using lights, stereo, etc. my starting battery is being drained, but not the house battery. I don't think it's always been this way. Input appreciated.

Andy

howardrams

Sounds like you have a total of 2 batteries, right?  And it sounds like you're saying whether the switch is on 1 or 2, you are really just using the same battery. That is not the intent of how it should be wired. You might want to double check that by temporarily disconnecting one battery and then the other to see what still works.  I can't think of any part that could have failed to make it do what you describe unless it has always been wired that way.  To me it sounds like 1 should be starting, and 2 should be house.  Or vice versa.

When I had an older Fiesta Vee, 1992 everything could be run from either battery 1 or 2, including starting, accessories, trim tabs, refrig, etc.  Rinker installed identical starting batteries, neither was truly a "house" deep cycle type.  So when anchored overnight you'd use either 1 or 2, play your radio and run your refrig and you'd switch to both in the morning to make sure you had the starting power of the other battery in case you drained one dry.

Their newer boats are different with the switch saying "on" or "combine/emergency" and I don't know in which model year they made the change.

[Deleted User]

Thanks howardrams. Yes, dual batteries.  If I disconnect a starting battery cable there is no power to the helm in either switch position #1 or position #2, only in the combined position. This is weird.

Andy

howardrams

I guess there could be bad contacts inside your selector switch or related circuitry.  Blue Sea Systems has some good product options and typical wiring info on their site:

https://www.bluesea.com/systems

[Deleted User]

Good info, thanks. I have bought a number of Blue Sea products and they are excellent.
Andy