Volt meter gauge installation wiring

fishon71

Chief Petty Officer
Joined
Jul 21, 2002
Messages
575
Because of my recent history with no charging, I want to install a volt meter to insure she is always putting out.<br /><br />Can the wires just be attached to the fuse panel (+/-) or do I need to run them direct to the alternator output from the engine or on the battery ?
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Volt meter gauge installation wiring

The positive lead of the gauge must go to a +12V line that is active only when the ignitiion switch is on. Ground to the ground buss. Light to one of the terminals on one of the other lights or to the switch.
 

swist

Senior Chief Petty Officer
Joined
Jul 1, 2004
Messages
678
Re: Volt meter gauge installation wiring

The positive lead of the gauge must go to a +12V line that is active only when the ignitiion switch is on. Ground to the ground buss.
Why do it this way? The battery condition when the engine is off is more interesting than when it is charging. My voltmeter is always on as long as the battery switch is on. They don't use any power to speak of....
 

Silvertip

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Sep 22, 2003
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Re: Volt meter gauge installation wiring

Swist -- There is nothing inherently wrong with your installation but I do question why you feel the "static" voltage reading is of any value. In your situation, the battery with little or no load may very well show 12.6 volts. Hit the key however and starter draw can pull that voltage to less than 9 volts and there you sit. Granted, switched or unswitched, the situation is the same. I just question the value of the static reading. Except for bilge pumps, boat manufacturers wire voltmeters and any other accessories so they are inactive when the ignition is off. The poster indicated he had a charging problem so voltage readings running are far more important than static. I personally don't want anything powered except the bilge pump when the switch is off.
 

swist

Senior Chief Petty Officer
Joined
Jul 1, 2004
Messages
678
Re: Volt meter gauge installation wiring

I didn't say it was on all the time, like the bilge pump. But it's on whenever the battery switch is on in any position - so I'll know if I'm running down the battery by excessive use of accessories when the engine is off.
 

Silvertip

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Sep 22, 2003
Messages
28,771
Re: Volt meter gauge installation wiring

I understand that and if it works for you -- great. My only point here is that a battery with very little reserve capacity left will measure 12.6 volts so the value of that reading is questionable. Once a battery begins reading less than 12.6 volts its ability to start a motor (at least a bigger one) becomes questionable.
 
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