Charging system questions

natemoore

Master Chief Petty Officer
Joined
Jun 13, 2009
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844
I've been worried that my battery wasn't being charged lately because my voltmeter only shows 12 volts all the time, except when I turn on the blower or bilge pump, then it dips. I've got 14.6 volts at the battery terminals. Was wondering if my voltmeter was inaccurate, so I ran a wire from battery (+) to the positive post, first removing the purple wire. It jumped up to 13 volts on the dial. I'd love to see that while out on the water so I'll know the battery is being charged.

Shouldn't the gauge be closer to the actual battery terminal voltage? There must be a voltage drop somewhere, because the purple wire at the gauge only showed about 12.5 volts (I forget the exact voltage). What would you check first, the big 10-pin plug by the engine? Corrosion there?

Another 1.5 hours on my new SEI 106 and I can go fast!
 

natemoore

Master Chief Petty Officer
Joined
Jun 13, 2009
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844
Anyone? Is there normally a voltage drop between the battery and the gauge?
 

CFM56-7

Seaman Apprentice
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Oct 22, 2013
Messages
49
I'm not sure exactly how your system is setup, but my voltage gage measures ignition sytem feed voltage(purple wire), not system(battery) voltage.If your setup is similar to mine, and the gage doesn't accurately reflect purple wire voltage, then the gage or gage connection may be faulty. If it does accurately reflect purple wire voltage, you may be getting voltage drop somewhere in the system. Could be the ignition switch itself, a kill switch, or something else wired into the ignition system. Or just a bad connector somewhere.
 
Joined
Mar 27, 2010
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3,008
Check to see what the voltage is going into the ignition switch.

If still only 12 volts then will have to trace the wiring back until you get to the wire that supplies the helm with constant battery voltage for the ignition and the accessories. Probably a large red or orange wire. if that still reads only 12 volts it may be time to replace that wire back to the stern.

I wonder if weak/bad ground wire could cause voltage drop also......
 
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natemoore

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Jun 13, 2009
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