Charge light coming on

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cardude01

Guru
Joined
Nov 26, 2012
Messages
5,290
Location
USA
Vessel Name
Bijou
Vessel Make
2008 Island Packet PY/SP
ImageUploadedByTrawler Forum1437493826.138320.jpg

The charge light came on after about three hours of running. Checked voltage. 13v.

Turned off the engine. Belt tight. Fired it back up and no charge light. 14v.

Any ideas?

Ps. The light is not on in this pic. Just showing what panel looks like.
 
Sounds like an alternator getting ready to give us the ghost. 13V is probably your battery voltage with residual voltage remaining from charging. Can you remove the alternator for bench testing?
 
Not very easily removable.

I'm 11-12 days from home, where I would like to work on it. Wonder if it will last that long?

Why would shutting the engine down cause it to charge again?
 
Not sure, but maybe restarting the alternator re-excites the field.

Can you turn off your key switch while the engine is running without stopping the engine or harm to your equipment? On my old Perkins, I can turn off the key which removes current from the start circuit and stops the alternator charge. Turning the key back on (not to the momentary start position) re-energizes the circuit and restarts the alternator.

If yours is similar, it might help diagnose the issue by selecting OFF, then ON with the key when the alternator drops off line.
 
Agree with Al.
You didn't say if it was an internal or external regulator, but there are so many things it could be. Be sure an eliminate all the obvious ones first. Check all the connectors from the alternator and battery, loosen, clean and retighten.

But as Al pointed out the alternator could be on it's last legs. They can get flakey before they finally die. Looks like you're a single engine, so If you're going to be out of touch with civilization during the next 12 days on your trip, I would want to fix the problem before going on.:blush:
 
Last edited:
On my system the Hino manual says not to shutoff the ignition switch with the engine running or damage to the alternator will result.


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Agree with Al.
You didn't say if it was an internal or external regulator, but there are so many things it could be. Be sure an eliminate all the obvious ones first. Check all the connectors from the alternator and battery, loosen, clean and retighten.

But as Al pointed out the alternator could be on it's last legs. They can get flakey before they finally die. Looks like you're a single engine, so If you're going to be out of touch with civilization during the next 12 days on your trip, I would want to fix the problem before going on.:blush:


It is a Balmer alternator and there is a Balmar duo charge before the batteries, but that's a splitter and not an regulator I think.

I guess it has an internal regulator.

I haven't had this boat long enough to figure out the charging system obviously.
 
CD, didn't you recently have a battery failure and replacement? That might also point toward an alternator/charging problem...
 
I did recently replace the house bank and start battery, but never did any diagnosis on why they went bad.

I was just figuring age since they 6-7 years old, but maybe the alternator killed them?
 
On my system the Hino manual says not to shutoff the ignition switch with the engine running or damage to the alternator will result.


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I shut the engine down and then turned the key off. Mine Yanmar book says the same thing.
 
On many setups the charge light just shows a difference between the batts V and the alt V.

With a long run , good batts and no DC load , many will not see a charge light, its too dim..

Next time it happens turn on a big user , the windlass or a bunch of DC items and see if it does not get brighter.
 
It could be that your alternator is entering the float stage of charging and the light is not smart enough to know the difference. My Balmar alt with the Balmar external regulator is set to enter float after 4 hrs.

Perhaps you have a smart regulator on that alternator and a dumb "idiot" light?
 
On many setups the charge light just shows a difference between the batts V and the alt V.

With a long run , good batts and no DC load , many will not see a charge light, its too dim..

Next time it happens turn on a big user , the windlass or a bunch of DC items and see if it does not get brighter.


Ok. Will do. Thanks.
 
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