Merc. 4.3 Charging Voltage

jkimball

Petty Officer 1st Class
Joined
May 14, 2013
Messages
220
About a month ago, my boat stopped abruptly while underway and the ignition switch and all gauges went dead. But it started right up in the driveway once I got it home.
For good measure, I replaced the breaker, ignition switch and checked all fuses.
I have traced the problem down to the dual battery switch (perko) and have one on order. It has a dead spot in it and won’t go to the #2 position so I know it’s toast.

anyhow, my question is really around my charging voltage at idle. The gauge indicates it’s around 14.7V if I am reading it right. This is at idle... I don’t remember it being so high prior to the switch SNAFU. Two questions -
1. Is this high enough I should be worried?
2. Did my alternator rectifier possibly bite the dust?

should I be concerned or just keep on boating? It has no other issues.

see pic
 

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alldodge

Moderator
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Mar 8, 2009
Messages
40,582
Normal is 14.5V once the motor first revs above 1000 or so rpms.
Not all boat gauges are accurate, get a hand held voltmeter and measure at the alternator orange wire and compare.
 

jkimball

Petty Officer 1st Class
Joined
May 14, 2013
Messages
220
Normal is 14.5V once the motor first revs above 1000 or so rpms.
Not all boat gauges are accurate, get a hand held voltmeter and measure at the alternator orange wire and compare.

Thanks! Will do.
it doesn’t seem egregiously high, and haven’t had any ‘symptoms’ so to speak. Just want to be confident all is well
 

Bondo

Moderator
Staff member
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Apr 17, 2002
Messages
70,468
Ayuh,..... Most boat gauges I've seen read 'tween 13.6, 'n 14.8,..... when chargin',.....
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
11,802
put a digital voltmeter on your battery, if you're in the range of 14.2--14.5 that's fine, dash gauges are often off. I had an issue with my OMC that caused excessive resistance in the S (sense) circuit and the batteries were being overcharged, at 15.2V so I wound up doing some re-wiring around this issue and now have normal readings on the dash gauge and on the batteries themselves.
 
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