www.iFourWinns.com

4.3 battery not charging but alternator putting out. Any ideas?

What is the voltage that it is putting out??

14-18 volts under load but battery is not charging at all. Took alternator off and had it tested. I was wandering what to check next. Wires and connections were tight. Battery charges with electric charger. This is a 2008 Horizon 200.

18 volts is way too high. It should be around 14.5 volts, I would have to look it up. I would check you battery switch next.

Is the circuit breaker tripped? I have 70 amp circuit breakers in the path between the alternator and batteries.

_________________
2004 Vista 298
Twin 5.7L Volvo Penta GXi-E

At what point are you checking the voltage ?

If it's at the battery, that 18V is probably going to have boiled off the electrolyte and it's new battery time, after sorting out the alternator.

If the voltage at the battery is low when the engine is running, but high at the alternator, it points to a break in the connection to the battery somewhere. Still, that 18V really is too high. !

Is that 18V too high if it is a high-output alternator? I don't know how those usually rate so I might be off on this. But something to think about if an HO alt puts out that kind of voltage.

_________________
Paul
2007 Four Winns Horizon 220
Mercruiser 350 Mag MPI w/ Bravo III Drive
2004 Ford Explorer Limited (V8-AWD)
Pomme de Terre Lake (Southwest Missouri)

High output refers to the amperage, not the voltage. If it's a 70 amp alternator or 200 amp, it's still going to output around 14.5 volts. Depending on your boat generally it's going to read less at the gauge due to voltage drop in wiring (upwards of 1v less), that's why you always check at the battery with a meter.

If you're getting raadings of 15+ volts, could be a few things. Could be as easy as just a bad regulator (usually internal now a days so that = get a new alternator). Could also be the battery voltage sensing wire has a break or is corroded somewhere. If the regulator isn't sensing battery voltage it will get stuck wide open and overcharge.

Either way, if you're getting above 15v time for a new battery after you fix the charging issue.


Depending on your alternator, if it's this style I'd check what T2 is doing. The marine world uses a bunch of other ones but it's a start.
http://i1339.photobucket.com/albums/o72 ... b7e165.jpg

_________________
1981 Columbia 8.7
2015 Yamaha FZR - 87mph - sold
2006 Yamaha GP1300R - sold
2003 Chaparral 215 SSI - sold
2009 Stingray 195CS - sold
2000 Four Winns H180 - sold
1976 O'day Daysailer II - sold
Rick's Four Winns H180 Mods/Upgrade Thread

The 18 volts was under load and 14.5 normal. I've got to check w iring and circuict breaker and will let you all know what I find. Thanks to everyone for the info. The owners manual has very little info on wiring etc. My Dad has a Sea Ray and it has much more info. Maybe I can get it before the big weekend! Battery has plenty of water in it as well as charges with an electric charger. It is putting out plenty of voltage to the coil to keep it running.