Aux Power will Fade Out

[corbs]

After running for a little while with the stereo playing and/or lights on, the stereo volume will slowly decrees and the light brightness will to until they stop completely and I will loose all power to the auxiliary options. The boat is running the entire time and it says the alternator is putting out around 14V. I can turn the boat off and start it no problem but the auxiliary power will not come back until I switch the red battery switch on the back to both batteries and even then it will only run half capacity. I can not seem to fix this problem can any one give me some incite to where to start diagnosing this problem.

[chpthril]

What year and model boat?

[corbs]

Sorry I forgot to include that in my first post. It is a 2012 RZ2

[Surf406]

Have you load tested your batteries to make sure there holding a charge ?

[chpthril]

Going to need a basic digital volt/ohm meter and a means to run engine.

Need to start by checking the voltage state of both batteries. My guess is that you will need to recharge the house battery. once the battery is fully charged. Need to start engine with switch in the ON position, goose the throttle a couple times to make sure you get enough rpm rise to insure the alt starts to charge.

Check for alternator voltage at both batteries. This should be in the 13.4+ range. We want to make sure both batteries are seeing input from the alternator. Do this with the meter's ground lead connected to the battery post that the main boat engine ground cable connects to. Lack of alternator charge at the house battery can be a ground cable issue same as it can be positive cable issue.

If there is not alternator charge voltage (only battery voltage of 12.5 or so) work back words on the positive cable till you find the point where you get voltage. This is likely a 6 or 8 gauge cable that runs to a 3 cable/post aluminum finned block mounted to the transom or front engine bay wall. This is the diode isolator, which I think the 2012 still uses.

The center post comes in the alternator. the outer 2 posts go to each battery. They may not go directly to the battery, but indirectly via through the main battery switch.

Back the ground cables, if the house bank is not properly linked to the main bank through a ground cable run between the two battery ground posts. This cable tends to go rogue and gets lost when the batteries are serviced. Without this ground link, the battery never sees alternator voltage.

[corbs]

We got this boat last year and I am not sure if the previous owner even had the batteries hooked up correctly. I should check that first... What is the correct way for them to be connected?

[chpthril]

I can tell you electrically, how the cables to be run, but I cant remember their exact physical connection points. I dont recall if tige ran the diode isolator outputs direct to the battery B+ posts or to the main switch. Electrically its the same in regards to the alternator charging, but physically a difference.

[corbs]

I am looking for the correct battery hook up connection. If you can provide that, that will get me started knowing everything is hooked up correct.

[trevor]

Like Mike said, if the only problem you have is that the house battery is not recharging, there are really 3 only potential issues. Missing ground, missing charge from the alternator, and that the alternator does not work, and your crank battery is going to die too. I am just re-wiring mine to add additional battery capacity, an onboard charger and acr, and trust me anytime I had a question mike knew the answer so I highly recommend following his troubleshooting advice before pulling everything apart and starting over, but thats just my .02.

On my 09 there was a diode isolator, sandwiched between the two transom lockers way up near the deck. The two cables leaving the isolator are labeled primary and secondary isolator, so you can make sure both of those cables are present. I believe these are 4 gauge.

The ground cable is even easier to check, as that is just a 2 ft long heavy (I believe 1 gauge) black cable between the two batteries, and a 1 gauge hooking up from the engine to the crank battery. I dont have pictures of the original setup and am almost done with the conversion, but hopefully this makes sense.

Sent from my SM-N950U using Tapatalk

[chpthril]

Tige may be able to email you their original battery/switch schematic, but I fee you will still need to jump in there with a volt meter. There faults that can be, even with the cables routed correctly.