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  #31  
Old 03-14-2013, 10:15 AM
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Originally Posted by JimN View Post
That doesn't mean it's correct. At rest, a charged battery should be over 13VDC.
Yes with mine @ battery and alternator it's right on the money, I will eventually need to redo my harness as I am having about a .75v drop between engine and dash.
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  #32  
Old 03-14-2013, 10:35 AM
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Originally Posted by FrankSchwab View Post
First of all, don't even think about pulling one of the battery cables on anything built in the last 50 years. If the Alternator is charging, and you remove the battery from the circuit, you can get a spike of upwards of 50 volts out of the alternator for a few hundred milliseconds until it can shut down. It's called a load dump, and will destroy any unprotected electronics in the boat (ECU, Radio, etc). Most auto/marine electronics were protected when they left the factory, but the protection circuits aren't always reliable. This trick worked great on pre-integrated circuit cars (you know, when the ignition had points and the radio had a pointer on a string for station selection), but it's a good way to "Break Out Another Thousand" with anything remotely modern.

Buy the Voltmeter; Harbor Freight will sell you one for $5 ($3 on sale). We buy them by the truckload at work, because a new meter is cheaper than replacing the battery. We use them for testing the computer chips we design, so we're pretty picky. These things are plenty accurate.

Put the voltmeter on the battery. If the engine's been off for awhile (say, overnight), the battery should read 12.6 volts. Once the engine is up and running and the alternator starts charging the battery, the voltage will go up, as high as 15V but generally around 14.4V. If the battery is very low, it'll take awhile for the battery to make it up to 14.4V, but it should always be above the voltage that it started at.
Great thank you! Getting a voltmeter today!
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  #33  
Old 03-14-2013, 10:37 AM
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If you have a '96, as your name indicates, don't screw around with "shade tree" stuff. I didn't see Frank's post before I commented, but a meter is so cheap there's absolutely no reason to be without one if anyone might have even a small chance of using it. Of course, this comes with the need to learn to use it, but it's not difficult.

If you have problems with the battery being dead or depleted when you haven't run the engine for a few days, it could have a bad alternator. If it doesn't show lower voltage after running it, make sure the belt is good and it's tight enough (don't over-tighten, though).

If you have no idea about anything electrical, remove the alternator out (or have it removed) and take it in for testing. The easiest way to deal with a faulty alternator is to have the old one rebuilt- that way, you don't need to search for the same type or try to make something work when it wasn't intended for this engine.
Awesome, thanksk a lot for the help!
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  #34  
Old 03-14-2013, 10:38 AM
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Originally Posted by j.mccreight@hotmail.com View Post
Yes with mine @ battery and alternator it's right on the money, I will eventually need to redo my harness as I am having about a .75v drop between engine and dash.
Thanks for the ideas man, I'll keep yours in mind as well!

Looks like the best way is to buy a voltmeter though. haha.
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  #35  
Old 03-14-2013, 11:59 AM
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Originally Posted by j.mccreight@hotmail.com View Post
While I agree with what you and the other guys, the OP wanted a way to check WITHOUT a multimeter, yes they are cheap. Right or wrong I was merely giving what the OP wanted...
OK, but this is fine with an older boat, this is not so fine on new ones.

Better to give them what they need, IMO.
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  #36  
Old 03-14-2013, 12:01 PM
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Originally Posted by j.mccreight@hotmail.com View Post
Yes with mine @ battery and alternator it's right on the money, I will eventually need to redo my harness as I am having about a .75v drop between engine and dash.
I would start by just cleaning/tightening the connections- hopefully, this will take care of it. Ever done a voltage drop test (from one end of each wire/connection, not just from the battery to each point)? That speeds things up, considerably.
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  #37  
Old 03-14-2013, 01:02 PM
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Originally Posted by JimN View Post
I would start by just cleaning/tightening the connections- hopefully, this will take care of it. Ever done a voltage drop test (from one end of each wire/connection, not just from the battery to each point)? That speeds things up, considerably.
Right O, I have done that on the engine harness to battery and all those connections are verified clean and tight and have the appropriate voltage my issue is from the engine quick disconnect plug up to the dash, I have not yet pulled floor boards and dash panel to check from engine forward, I have a gut feeling it's actually my ignition switch is the problem...
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  #38  
Old 03-14-2013, 01:03 PM
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Originally Posted by j.mccreight@hotmail.com View Post
While I agree with what you and the other guys, the OP wanted a way to check WITHOUT a multimeter, yes they are cheap. Right or wrong I was merely giving what the OP wanted...
Sometimes in life, like being a doctor, you have to give people what's right rather then what they want. Doing more harm then good even when someone ask is not the right thing to do.
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  #39  
Old 03-14-2013, 01:32 PM
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Originally Posted by j.mccreight@hotmail.com View Post
Right O, I have done that on the engine harness to battery and all those connections are verified clean and tight and have the appropriate voltage my issue is from the engine quick disconnect plug up to the dash, I have not yet pulled floor boards and dash panel to check from engine forward, I have a gut feeling it's actually my ignition switch is the problem...
I have seen switches that caused voltage drop- if you connect the voltmeter on the battery terminal of the switch and the other probe to the Run terminal, measure the voltage. It will be a small number and this is your voltage drop across the switch. If you see mV, it pretty much rules out the switch as the cause of the problem. Likewise, if you suspect a cable terminal, you can connect to the side of the terminal closest to the battery and at the far end of the terminal. If you see much drop, it tells you there's a problem and this is really helpful when trying to find out why a starter cranks slowly because damage to a + battery cable can't always be seen.
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