2004 SAN210TE Won't Maintain Voltage! Any Ideas?

[SCNautique210SAN]

Hey Guys,

Trying to figure out why the heck I can't get my system to maintain high enough voltage to shut the voltage gauge beep up when it's in accessory (perko is set to "All"). I've attached an image with my current configuration. The batteries are less than 2 years old. Just fully charged them within the past week but I'm still having the issue.

Took my volt meter to both batteries (with perko off to seclude them). Both were reading 12.48 volts. But, as soon as I turn it onto accessory and give just a tiny bit of volume to my stereo, or turn on the ballast pumps, or turn on the lights, etc (could be any of them), it starts beeping at me and can't maintain voltage.

I'm stumped. I feel like between these two batteries, it shouldn't be an issue when they're both fully charged and the Perko is set to pull from both batteries. Any ideas??

[Fgroce]

I would check all the grounds for corrosion, you can also check the voltage at the back of the alternator to the ground on the engine. With the engine running at about 1500 rpms it should be 13.4 to 14.0 volts.

[ck1105]

My 2003 was doing the same thing, I followed wires, tested everything possible, and it ended up being a failing alternator. It would only intermittently charge, it was barely enough to keep batteries "charged" I replaced alternator and everything is working perfectly. At least my boat is rewired now.

[SCNautique210SAN]

Thanks guys. So the voltage is fine when the engine is on. No problem there. It's when the engine is off and the batteries are fully charged. I'd expect the voltage to maintain the minimum when I turn on the bilge lol. Even if the engine is off.

Right now, the batteries are fully charged and the volt warning beeps when the engine is off when I put any load on the system, like the bilge or ballast pump. Was reading other threads and came across someone mentioning the leads to the dash might be corroded so I'm going to look at that but I checked all the leads on the battery and there's no corrosion on those.

Anyone else experience this?

[wakejunky]

I'm thinking alternator. I've got a similar year boat, 03', and I have two batteries that run in parallel when running via a isolating solenoid and isolated when only running stereo So, in theory I should have plenty of amperage to run the stereo and pumps but, I'm finding that my alternator can't keep up with my demands. They put whimpy 50Amp alternators in these boats back then because the current draw back then wasn't as high. Now as people upgrade stereos and pumps there is a higher demand from the alternator to provide the current necessary to run the accessories. The batteries are just banks of power, think of them as a pool, you can drain a large amount of water out of the pool quickly (with amps/pumps etc) but, filling it with a garden hose will take forever, whereas filling it with a fire hydrant wouldn't take much time at all. So, if you're draining more so than filling, you loose the ability of the batteries to provide the current that is being demanded from them. Hence needing a larger alternator.
I'm looking at upgrading my alternator to a 105AMP marine alternator and upgrading the wiring from the alternator to the boat wiring. In my initial investigation, I will probably change to a higher amperage circuit breaker and doubling up the existing wiring to account for the increased current capabilities.

[SCNautique210SAN]

I'm thinking alternator. I've got a similar year boat, 03', and I have two batteries that run in parallel when running via a isolating solenoid and isolated when only running stereo So, in theory I should have plenty of amperage to run the stereo and pumps but, I'm finding that my alternator can't keep up with my demands. They put whimpy 50Amp alternators in these boats back then because the current draw back then wasn't as high. Now as people upgrade stereos and pumps there is a higher demand from the alternator to provide the current necessary to run the accessories. The batteries are just banks of power, think of them as a pool, you can drain a large amount of water out of the pool quickly (with amps/pumps etc) but, filling it with a garden hose will take forever, whereas filling it with a fire hydrant wouldn't take much time at all. So, if you're draining more so than filling, you loose the ability of the batteries to provide the current that is being demanded from them. Hence needing a larger alternator.
I'm looking at upgrading my alternator to a 105AMP marine alternator and upgrading the wiring from the alternator to the boat wiring. In my initial investigation, I will probably change to a higher amperage circuit breaker and doubling up the existing wiring to account for the increased current capabilities.

Hey wakejukie looks like posted literally at the same time. But I was just mentioning that the problem isn't when the boat is on, it's when it's off. The batteries are fully charged and when the engine is off, any load on the system brings the voltage below the minimum and it starts beeping at me, even just the bilge. When the batteries are fully charged, it should maintain voltage even when the boat is off with something as small as the bilge pump or a ballast pump IMO.. Thoughts?

[wakejunky]

Have you done a voltage comparison at the batteries and at the dash? I know CC didn't have a large enough wire to the dash so, there was a drop in voltage and perfect pass would beep at you. The solution was to run a extra wire from the starting battery to the control box at the dash or to the switch on the starboard side and then another from the switch to the control box. If you go directly to the box then you can't "turn off" off your boat completely.
While you're at it check all your connections too, at the batteries, at the dash, even engine connections, alternator, starter and grounds. You need to make sure everything has good connections, you could be sinking voltage into a bad connection, path of least resistance.

[SCNautique210SAN]

That's my next step. Going to check to see if there's any corrosion anywhere and if need, add another wire.

[Tmosely1]

When you have the stereo playing... Can you see the voltage at the battery changing with your meter? Also... Wakejunky brought up a good point... Is it a perfect pass that is beeping? Because he is 100% correct that the power and grounding between the engine and dash is an issue. When I corrected mine, there were daisy chained grounds.

[SCNautique210SAN]

Tmosely1 I'll check again but I don't think there was voltage change at the battery. When looking at the wires at the dash, I assume the place to be looking is all in the breaker box right? Checking all of the grounds and power at the breaker box? Or between the breaker box and the dash?

[Tmosely1]

My issue in the dash was that most of the gauges (including perfect pass) were all attached to one single 16 or 18 gauge wire with a bunch of connectors attached. So the first gauge was happy.. second one was content... by the time you got down the line to where the perfect pass, it was not so happy with the ground and would trigger its voltage alarm. If there's perfect pass on that boat, I believe it will indicate on the gauge that it is seeing a voltage issue. Can you tell if its the perfect pass beeping?

[SCNautique210SAN]

Ok, so I checked voltages in a few places and here's what I found:

At the battery, it's at about 12.28 volts. On both sides of the perko it's the same voltage. At the master/automatic bilge switch it's at about 12.23 volts on both sides of the switch. But, by the time it gets to the breaker box, it's at about 12.09 volts. It's the same once you get to the power connector behind the gauges.

So it seems like something between the master switch and the breaker box? I tested the ground on the breaker box and it appeared to be just fine. I cleaned all of the connectors from the battery all the way to the breaker box too. No such luck.

Shouldn't the voltage be at 12.6 with two fully charged batteries? They can't be bad though (I Hope). I bought the red top only a year ago..

Thoughts?

[wakejunky]

The power and ground going to the break out box is insufficient, you need to run an extra set of wires from the battery to the box. Ground directly to the box and the power can either go to box or to the bilge switch and then another line from the switch to the box.

[SCNautique210SAN]

Is this something that just needs to be done with the age of the boat? Looks like the wires are 10 gauge which seems sufficient for the dash components. Didn't always do this either. Maybe the wires are corroded inside?

[Tmosely1]

In truth... It's really just an upgrade that most of us have had to do because of our accessories. It's sort of a self inflicted pain. Nautique had no idea that down the road of ownership that we would have nicer stereos..eq..amplifiers..a couple cell phones charging.. All those things are a draw on the electrical system they didn't know was coming. Im guessing they chose an alternator with less resistance to reduce the load on the engine.
You're also on to something else... I'm guessing that if you were to cut the insulation off of that wire, you may find corrosion.