battery voltage problem???

bfensom

Seaman Apprentice
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Aug 4, 2014
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I have a 07 75 merc efi that is giving me a warning if 3 beeps and Mercury told me its an issue with either battery voltage or the charging system. Before I take it to the mechanics and pay out the ass is there anything I can check myself and see if it's the problem?
 

UncleWillie

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Oct 18, 2011
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Start the Engine and measure the battery voltage.
If it is above 13.8v, (~14.5 typically), the charging system is fine.
If it is below 12.6v, you have a problem, and if it still starts the engine, don't leave the dock because it will be dead soon.

If the Voltage is above 14v with the engine running, shut it down and wait a few days.
If after a few days the battery measures less than 12.5v, the battery is weak or something is draining the battery.
If you still have at least 12.5v after a few days, Pull the safety lanyard to prevent the engine from starting, and then crank the starter for 20-30 seconds. If it is still cranking after 20-30 seconds, the battery is Good!
 
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alldodge

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I have a 07 75 merc efi that is giving me a warning if 3 beeps and Mercury told me its an issue with either battery voltage or the charging system. Before I take it to the mechanics and pay out the *** is there anything I can check myself and see if it's the problem?

My take is this is an outboard and the most probable cause is the oil injection system. Here is a post from jimh at continuouswave which explains what you may be hearing.
Any of the following conditions will signal a BEEP-BEEP-BEEP:
--oil level below the float switch level in the under-cowling reservoir
--input gear shaft to mixing pump turning too slow in relation to engine speed
There is no way to tell which of these events causes an alarm. You have to deduce which is the problem by inspecting the motor.
It is also possible that any of the following conditions will also signal a BEEP-BEEP-BEEP:
--defective float switch in the under cowling reservoir
--defective motion sensor in the mixing pump
--defective ignition module sending false signal
--defective alarm module creating false signal
Here is a link to the oil section
http://continuouswave.com/whaler/reference/mercuryOilInjection.html
 

bfensom

Seaman Apprentice
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Aug 4, 2014
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31
Ok so I checked the battery with the boat off, running and running with loads on and this is what I found

Standing batt : 12.38
Boat on : 11.98
Boat on with loads on: 11.93
 

UncleWillie

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Oct 18, 2011
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Does "Boat ON" mean Key On, Engine OFF. .... Or, Engine Running?

If Engine OFF, Numbers are normal.
If Engine Running, Alternator is Dead.

Warning Beeps before starting, and any time you have "Key ON/Engine OFF", is also completely normal.
 

bfensom

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Aug 4, 2014
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Thanks Unc and ya sorry boat on means engine running... Looks like I'll be making a trip to the Merc dealer lol
 

UncleWillie

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Be sure you have a good connection between the alternator and the Battery.
There could be a fuse somewhere in there that you blew when connecting wires.
The alternator should be showing the same 11.9 that you have at the battery. If different, they're not connected together.
 

airshot

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Jul 22, 2008
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I would consider a good quality alternator rebuilder if you have one in your area before taking it to the high dollar Merc dealer.....unless under warranty of course.
My experience has been a quality alternator rebuilder has the proper equipment to check marine alternators that auto parts stores do not. Have also found them to be much less expensive than a dealer and better quality workmanship. I am probably spoiled as I have one not far from me that has done wonders for people where others have told them alternators were not repairable. I am one of those people, I was told mine was junk and not worth repairing, however he did repair it for less than 50 bucks and it works better than it ever did even when new. That was three years ago and I know numerous others that have had the same experience.
 

bfensom

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Aug 4, 2014
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Any idea how to test the alternator myself first to see if it is the problem?
 
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