www.iFourWinns.com

Boat - in my signature.

I bought the boat and instantly realized that the #2 battery made the engine crank really slow. It also showed less volts on the dash gauge than the #1 battery. I replaced both batteries with new ones, cleaned cables & connections at the battery.

Put new batteries in - same problem. When switch is on Battery #2, the engine cranks really slow and the amp gauge shows less volts, engine off. With the engine ON and running, it overcharges battery #2, per the gauge. It never does this with the switch on Battery #1. When I take my multimeter and probe each battery, they both show exactly 12.6v, engine off. Running #1 shows 14v, #2 shows 16v+. Sometimes the volts get so high when on Battery #2, my VHF radio says "volt hi" and wont work Doesnt seem to appear on Battery #1 though....

I swapped batteries to make sure I didnt get a bad battery, same difference.

Im thinking the cables went bad on the #2 battery, but I do not want to go throwing parts at the issue. Any suggestions or places to start troubleshooting?

_________________
1997 Four Winns Vista 278
T - 4.3l EFI
Kohler 4esz Genset
379 hours as of 8/8/21

How do you switch them, from one battery to the other?? Is the a battery isolator? When you took the readings, was the shore power on to the on board chargers?? The more I think about it, I am going to say no, the on board chargers we off. But please, confrim. I would look at all the wiring going back to the battery switch. Make sure nothing is shorted, like a pump, just a thought?

Thanks for the reply, Paul.

My Guest marine onboard charger is, of course, NOT on during these episodes.

I do switch the batteries with the engine off and I have a Guest switch at the transom, installed by Four Winns from the factory. It is the typical 2 battery switch (Off-Batt1-Both-Batt2). I never use the 'both' setting.

I have no shorts. Nothing electronic is running when this occurs, not even the stereo. I have tried ruling everything out that I possibly can - Ive had the alternator rebuilt, the starter rebuilt, replaced both batteries, cleaned the battery connections several times (my neighbors probably think Im nuts by now, lol), and traced all of my fuses in the fuseblock. Everything checks out.

The one thing I do not know, is if the boat has an isolator. If it didnt come from the factory from Four Winns in 1991, then Im guessing it doesnt have one. But would Four Winns sell a 26' boat with dual batteries and no isolator?

_________________
1997 Four Winns Vista 278
T - 4.3l EFI
Kohler 4esz Genset
379 hours as of 8/8/21

If you don't see a isolator, than you don't have one. In other word, it would be "right " were you could see it with the battery cables coming off of it. Try, disconnecting any secondary wires off the batterys and switch. I am thinking that something small is running, like a pump that is putting both batterys in series to come up with 16+ volts. Or it could even be the charger, something could be breaking down in it? Another thing, have you tried swapping the batterers. Does the problem fellow it?

Answer....

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One of 4 Previous (Sold) Boats:
2000 Four Winns 268 Vista

Current Boat: 2004 Chaparral 235 ssi cuddy

You don't miss a thing, do you!!

My battery cables go right from the battery to the battery switch, then to the starter & ground.

There are times when I dont plug the battery charger in for weeks at a time. I also just installed the battery charger late last season, and had this problem before the charger was installed. In fact, I installed the battery charger because I thought #2 wasnt getting a charge from the alternator, although I can confirm it is while the engine is running and on battery #2 (it will read 15-16v+, with a multimeter at the posts on battery #2).

So what would cause #2 battery to overcharge when they both have a sitting voltage of 12.6v. Its obviously not dead, and theres nothing running in the background. I can switch over to battery #1 and it cranks normal and charges normal. They are both new batteries, and Ive swapped them back and forth to no avail. If I dont use the boat for a week, the batteries dont discharge at all, so nothings bleeding power either.

Can battery cables themselves go bad? Thats the easiest thing I can think of.....

_________________
1997 Four Winns Vista 278
T - 4.3l EFI
Kohler 4esz Genset
379 hours as of 8/8/21

Yes they can.

Based on the fact that switching batteries causes the same behavior on the circuit of battery 2 I would isolate my troubleshooting there.

I would take a meter to the circuit while it is running and verify that your gauge is in sync with the meter just to rule the gauge out.

From there I would look at the battery switch and make sure nothing wired to battery 2 has a short.

Good Luck.

_________________
Walter

2003 248 Vista - VP 5.0 GXi
2009 Toyota Tundra SR5 5.7L 4x4

When you are checking your battery voltage with the engine running, are you checking from the battery terminal + to the terminal - ?

Are both batteries grounded at the same point on the motor?

The only thing that makes any sense to me is the grounding point on battery #2 or the ground cable on battery #2. That would also explain the slow cranking on battery #2

_________________
Jeff

'14 Cruisers 380 Express "Simon Sez"
Merc 8.2 Mag MPI 380
DTS B3X, (x2) Axius Premier


(SOLD)
'08 V318
Merc 350 Mag MPI 300
DTS Seacore, B3 (x2)

Yes, the cables can go bad. That would explain the slow cranking, BUT not the 16V and overcharging. Thats why I did not mention it. You could change out the cables, if you do, I would go one size bigger. I find that FW likes to undersize there wiring.

Agian, disconnect any & all secondary wiring from both batterys and switch. I would do this one wire at a time and take a reading from both batterys. If you remove the "right" wire to the helm, the engine may not start. Thats why I say, one by one & take a reading.

As I was writing the above, what came to mind is the battery switch. Try bypassing it, it shoud have nothing to do with it. But maybe corrosion is shorting the contacts? You can use a 1/4 or 3/8 bolt to tie them togther.

I had the main breaker trip on my old boat, it was a 70 amp breaker, I was getting low voltage at the dash due to the breaker being tripped, however when i put a meter on the alternator output, I was getting 19 volts. As soon as the breaker was reset, it went ot normal.

If a bad ground couldn't cause an over voltage, how would you think a bad cable could. It would basically be the same thing.

_________________
Jeff

'14 Cruisers 380 Express "Simon Sez"
Merc 8.2 Mag MPI 380
DTS B3X, (x2) Axius Premier


(SOLD)
'08 V318
Merc 350 Mag MPI 300
DTS Seacore, B3 (x2)

If I am misunderstanding you, sorry. But I never said that ether could. I did say "Yes, the cables can go bad. That would explain the slow cranking, BUT not the 16V and overcharging." What I don't understand is "it was a 70 amp breaker, I was getting low voltage at the dash due to the breaker being tripped" If the breaker was tripped, how could you read any volatge? Unless the breaker was bad or bad wiring in the boat.

But to get back to piont, I am not clear to what your low volage problem, has to do with over chargeing? Now if a cable was bad or going bad, you may not see a volage drop with a meter. But you will see the current being limited (slow craking) in the cable. To put it another way, the cable will act like a big resister. It would not add to the voltage.

You say a bad ground, it could be!! I am not there! Most dual set ups, use one ground and than use a jumper from one battery to the other. That jumper could be bad or going bad since the problem is only with the #2 battery. But I don'y understand how the volage & overcharging could go up. But it is too simple not to try & see if that is the problem!

Wow! Thanks for all of the replies folks!

To clarify, I have checked the battery with a mutimeter by taking the red probe and putting it on the + side of the battery, and the black probe to the - side. BOTH batteries, engine off, battery charger not plugged in - indicate 12.6v. Although multimetering the posts of the battery return good volts, my dash gauge shows lower volts on the #2 battery, with engine OFF. With engine on, for some reason #2 will also get overcharged (16v+ at times!).

Using the multimeter on the battery posts, when running on #1, it will show charging around 14.5v or so. When Im running #2 battery, it will show charing at 15-16v+.

Both batteries share a common ground. My #2 battery black battery cable goes to the back of the engine block. #1 battery is connected to the #2 battery via a cable thats about 2' long and just goes from the - post of the #1 battery to the - post of the #2 battery. My last Four Winns (99 Vista 258) was set up the same exact way.

I bought the boat April 2010. Ive noticed that there are several parts of the red battery cables of both batteries that have black electrical tape wrapped around them - Ive taken the tape off and there is no damage underneath. I have no idea who wrapped rings of electrical tape around the positive cables and why After all, the boat is 20 years old and Im the third owner.

How could I rule out a bad battery cable? It seems on the #1 battery, the boat is getting the full power out of the battery but on #2 some of the volts are getting "lost" somehow along the way. Maybe the alternator doesnt sense that #2 battery is charged fully, thinks its discharged because of loss of volts through a bad cable, and overcharges to compensate??? My head hurts...lol.

_________________
1997 Four Winns Vista 278
T - 4.3l EFI
Kohler 4esz Genset
379 hours as of 8/8/21

OK, we now know it is not a bad ground, at lest to the Neg battery cables. As to the cables, look for corrosion. If the boat is that old, I would replace the cables anyways. Try my suggestion over the weekend and let us know. Just be careful not to short any thing out.

Paul - should I replace the positive battery cables AND the big red cable that goes to the starter?

West Marine is going to love me this week...dropped a bill there yesterday, stopped on the way to work spent another bill (needed a burner for my magma grill and a few other things). Now Ill be going to get battery cables made (knew I shouldve bought West Marine stock when I had the chance, lol)

_________________
1997 Four Winns Vista 278
T - 4.3l EFI
Kohler 4esz Genset
379 hours as of 8/8/21