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wrote:
OK, assuming the alternator is good. you need to check all your
connections. You've probably replaced everything, but double check
stuff anyhow. some wires maybe attached to the battery terminals, that
may have been left off. It's a wild shot, but I'm mentioning it anyway.

another thing, you may have gotten a bogus battery. charge overnight
on a slow charger then take it in and have it tested. it could have
come from the store with a weak cell. Just because it's "new" doesn't
mean it's "good"
But still, I would think that even with a bad battery, your volt guage
should still be above 13v when running.

an old rule of thumb is a decent charge when running is your alternator
will put out a rating of 13.8-14.2 v. providing you have a decent
battery.

Christine wrote:
As far as I know, the allternator was fine before this happened. Replaced
the battery due to negligence (previous owner left it in the boat all
winter).

Mike

wrote in message
ups.com...
Did it seem to be working fine before you changed the battery?

probably not.

I'd say you need to take the alternator to a competent shop and have it
tested.

If it's a Mando, or Prestolite/Motorola, the shop will know whats going
on unlike taking it to a parts store for testing, because they don't
hook up like conventional automotive units.

Christine wrote:
Vessel: 1999 Maxum 1900SR
Engine: 4.3l Mercruiser w/Alpha I drive
Issue: Battery is being drained by ____(something).

Details: Installed a new 550 CCA Marine Battery about 3 weeks ago. Ran
great when first installed. Boat sat for 2 weeks, tried to start -
"click".
Nothing. Was able to jumpstart from the truck, ran it for about 15 min
top
charge. Voltmeter on the boat dashboard reads 10.5 volts. Hand-held
voltmeter at battery reads 13.98; test at alternater reads the same.
Took
battery back to dealer & had tested. Battery OK, fully charged.

So, I think the alternator is OK. No visible frayed wires & such. My
gut
tells me that the voltmeter in the dash is suspect since it reads
differently than the hand-helds.

Any sugggestions as to what could be draining the battery or anything
else
typically to look for?

Thanks,
Mike

OK, so it sounds like your alt. is working correctly. a "volt meter"
is a simple thing. it usually has a ground wire which grounds the
meter, eventually to the battery. and the positive side has a "red"
wire that is attached to any switchable source. so..with key off, it's
dead(0) with key on, you have battery voltage,( 12.6 v.+/-) and when
running and charging
(14 v +/-) the volt meter could be defective, like it's had water in it
from rain water etc., but it shouldn't have any effect on the battery
draining . because when the power is shutoff. the guage is also shut
off with no current to feed it.off. now, if you shut the key off, and
still have a reading in the gage, then you may have power leaking to
it, via a defective relay somewhere. it does sound like you're working
int he right direction.

Here's something else you can try. another wild shot, but....

This is a fred flintsone alternator test. wit all hooked up, and the
key off. take a screw driver and place it against the back housing of
the alternator, where the back bearing is. and see if you have a
magnetic draw. there may be a slight amount due to residual magnetism
in the alternator field rotor, but it should be almost nothing. Turn on
the key and try again. if you have a pretty good pull ( it won't suck
it out of your hand) then you may have voltage coming from your key
switch or again, a shorted relay that is causing power to be fed to the
alternator. and the rotor, will take a 4-6 amp draw. thus a drian. It
would be like coming home and before getting out of your car, shut off
the car then turn the key back on and go to the house. alternator is
energized and pulling current. if that's the case hten pull the wires
(Motorola well say "exc." Delco will be wire "1" on the plug end, and
Mando will be the "purple" wire) use a test light, hook to ground (Bat
-) or direct to engine, and test the wire . if you have power on the
field or "exc." wire with key off, then you either have a defective key
switch (unlikely) or a bad relay (somewhere) or that wire kissed and
mated up to a Pos. "hot" wire.

More search and siezure....

you made mention of a thin red wire attached to the battery with a
fuse. That wire is the main hot wire that goes to the main harness ie
where the key gets it's power. if the fuse (30A?) blows, you probably
wouldn't have any power to anything.

I hope my ramblings are of some help.
-

On 6/19/06, Mike Salome wrote:
Thanks for your suggestions. We removed the battery &
took it back to the place of purchase, where it was
tested and found to be OK. So the battery itself is
not the issue.

I still think the volt gauge in the boat's dashboard
is suspect, since it only reads 10.5 volts with the
engine running, and our hand-held voltmeter reads
13.98 at both the alternator & at the battery (both
tests done with engine running).

In addition to the red positive main battery cable,
there is a thin red wire with a fuse that's attached
to the positive side of the battery. I wonder if this
wire is connected to the in-dash volt gauge, and if
it's damaged somewhere along the line, thus giving the
in-dash voltmeter a bad reading -- and possibly
causing the battery to drain or to not receive a full
charge from the alternator. I checked the fuse and
it's OK. Do you know if in-dash volt gauges are
normally hooked up directly to the battery or if
they're hooked up directly to the alternator?

Mike