Strange Battery troubles 2012 rz-2

[JTs-rz2]

I have the stock dual battery setup 2012 rz2. Battery tester shows 12 volts both batteries. TT2 Shows 11.7v in on mode and 1v in accessory mode. I get a low battery warning in accessory mode On 1 or 2 batteries.

When running with battery in 1 position boat operates fine for about 30 min. Then weird stuff happens. Stereo slowly dies off or is spotty. Taps will not adjust. Tt2 Buttons and screen do not work. I switch to both batteries then everything is fine.

None of my battery cables are marked or labeled. I cannot determine which battery is house or starter. I have 1 negative on each battery. 2 positive cables to each battery and then 1 extra small wire to 1 battery with an in line fuse.

I have not been able to duplicate off the water. Seems to happen after filling ballast on 1 battery position. I have been running at 1800rpm neutral when doing filling.

Ideas? Thanks

[IDBoating]

You can determine which is house and starter. You'll just have to follow some cables around.

Do you have a multimeter? Measure the voltage at the battery terminals, first as now wired and then with the negative terminals removed.

The point is, you're going to have to do some troubleshooting. This will involve tracing cables, disconnecting things, measuring voltages, etc.

It's interesting that you get a low, but not zero, voltage reading in accessory mode. If something really is pulling down a lead-acid battery that far, there is some SERIOUS current flowing somewhere. A dangerous situation. You're right to dig into it.

To get started, check the voltages as described and report back. Others will chime in too. We can help but you will have to be our remote eyes and hands.

[chpthril]

I have 1 negative on each battery.

The ground cable that links the two banks is not connected to the main cranking battery, there should be two large ground cables on it.

[JTs-rz2]

The ground cable that links the two banks is not connected to the main cranking battery, there should be two large ground cables on it.

Thanks. Found a smaller negative tucked way in back not connected. Figured the dealer would install the batteries correct.

Crank- 2 fat negative
House- 1 narrow negative.

What about the positives? I could not find a wiring diagram or layout.

I have 2 fats 2 skinny and one thin with an inline fuse.

[chpthril]

Sounds like you are still missing a ground cable. There is a main ground from the engine, which is a large 2/0. There will be a ground cabling linking the two battries. I think its the same size as the main ground. That thin one sound like the 4ga helm BUS ground.

[JTs-rz2]

I think I got it. I had 2 more positive side which must go to an acr that I could not locate. The inline fuse is plastic tied to a positive so I connected that to the house positive

Crank
1 negative from engine
1 negative from negative buss
1 positive from #1 switch to #1 engine
1 positive from ACR?

House
1 negative from buss
1 positive to #2 switch to #2 buss positive
1 positive from ACR?
1 inline fuse to positive from ACR?

[chpthril]

Missing the ground that links the two batteries. Without it, the house is standing alone and not part of the circuit.

[JTs-rz2]

Missing the ground that links the two batteries. Without it, the house is standing alone and not part of the circuit.

So there should be 4/0 or 2/0 connected from battery to battery on the negative terminal?

If so I will have to make one. Nothing left in the boat. Thanks skipper buds.

[JTs-rz2]

https://www.bluesea.com/products/821...ol_Switch-Gray

I don't see a battery to battery ground in any layouts.

[chpthril]

Every battery has to have a path to ground, in order to complete the circuit. This path to ground is eventually to the engine block where the alternator, which begins the circuit, mounts. This mounting is how the alternator is grounded.

Since Tige's first dual battery setup back in the early 2K's, they used a short ground jumper between the battery ground posts.

Those diagrams are general in nature. They show the electrical path of the ground, rather than the true actual cable routing. What they show is each battery going to ground. This is accurate in terms of electrical . However, connecting battery #2 ground to battery #1 ground, which is connected to the engine block, serves the same electrical path. This is what tige does.

[JTs-rz2]

Have have crank battery to engine ground. Crank battery to negative buss. Then house battery to negative buss. So I should have a complete circuit.

[IDBoating]

So check for a voltage difference between the negative terminals on the two batteries. There shouldn't be any, if they are properly bonded.

[chpthril]

Ok, so i was a little confused on your drawing and want to clarify. Ive drawn over your doted line with a slight deviation. Is this deviation correct? I was confused on where that doted line marked as 2/0 terminated.

2nd. This doted line and the one next to it marked as 4/0. Which one is the large one and which is the small one?

Electrically, i think the grounds are all there, based on that drawing, although they have been rerouted.

Time to break out the volt meter. I would also make sure the ACR coil control ground fuse is not blown. That would render the ACR to an open state, meaning no alternator voltage passes through to the house bank. However, turning the main battery switch to combine, bypasses the ACR.

[JTs-rz2]

Ok, so i was a little confused on your drawing and want to clarify. Ive drawn over your doted line with a slight deviation. Is this deviation correct? I was confused on where that doted line marked as 2/0 terminated.

2nd. This doted line and the one next to it marked as 4/0. Which one is the large one and which is the small one?

Electrically, i think the grounds are all there, based on that drawing, although they have been rerouted.

Time to break out the volt meter. I would also make sure the ACR coil control ground fuse is not blown. That would render the ACR to an open state, meaning no alternator voltage passes through to the house bank. However, turning the main battery switch to combine, bypasses the ACR.

Sorry no pic attached. Thanks for the help. I will check the fuse tonight.

[chpthril]

lets try again