need a sticky/link on how to use a basic volt meter

Joined
Feb 17, 2012
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Re: need a sticky/link on how to use a basic volt meter

"12V is easy .. GPOP . .. "

sometimes 12v on here is like pulling teeth. the basics like testing the meter on the battery to ensure it works takes a act of congress. then theres also the ones who go test crazy trying to use resistance to find a amp draw then want someone to explain where the 20 meg ohm reading they are getting is coming from. i was never looking to teach anyone how to use the meter i was looking for a refrence that shows someone how to set and preform a test so they could tell us the results of the test. try to explain how to put a meter inline from the positive side of the battery to test for amp draw normally leads to explaining how to replace the 10amp fuse in the meter and we get results from tests all the time that go against the laws of physics. i blame the modern volt meter for being way to complicated with to many options. after last night trying to help someone it finnaly clicked that some people will never get the basic idea of 12vdc so im not sure if there was a step by step guide on how to hook up a meter they would be able to follow it.

once you understand that some people can not get to grips with 12vdc then you know that theres no way we are playing with shore power other than to link them back to the code book for marine wiring
 

matt167

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Re: need a sticky/link on how to use a basic volt meter

I think this is what your looking for

I did make a small easy diagram that covers a basic Harbor Freight $3 DVOM ( I have a few ) which is available other places like Walmart also. I did hold off on uploading it, just to make sure it was wanted.. Didn't cover amperage, because not knowing how to hook it up, or the max amperage of the circuit can damage the meter. I'v also never had to use that function except in more complex cases.
Not great. I did it in paint.. No technical terms, no electrical symbols because I didn't feel like bringing the character map to input them, but it can be used for how and where to test

12v diag.jpg
 

bruceb58

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Re: need a sticky/link on how to use a basic volt meter

You dont really need a voltmeter in a 12 volt dedicated sytstem .
Really...you can't be serious! So if you have a circuit with an unknown voltage drop, how do you propose you measure it?
 

Grandad

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Re: need a sticky/link on how to use a basic volt meter

Before anyone expends a lot of time and energy or risks re-inventing the wheel, here's an excellent open source compendium on electric circuits which includes details on the use of meters. This information spans from the basic to the detailed. In my experience as a college professor teaching apprentice electricians, I judge this to be a terrific reliable resource and it's free.
Check it out. - Grandad

http://openbookproject.net//electricCircuits/

http://openbookproject.net//electricCircuits/DC/DC_8.html#xtocid69540
 

Don S

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Re: need a sticky/link on how to use a basic volt meter

guys we need to make a sticky/link on how to use the basic functions on a volt meter including voltages, resistance and inline amp readings. im no very good with graphic software so i was hoping some could make some simple drawing that we can link people to when asking them to take basic readings.

Tell you what Glenn, I'll do the graphics for you if you want to write it. We can make this for very basic 12V marine checks Volts, amps, resistance.

I have pictures, and can easily change things, you just tell me what you want in the picture and we can put it together.

Here is some things I already have made. It's in adobe Illustrator, so I can change size turn, move the meter probes or anything you need.

Untitled1.jpg from this to this in a few minutes. Untitled2.jpg
 

Yacht Dr.

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5,581
Re: need a sticky/link on how to use a basic volt meter

Really...you can't be serious! So if you have a circuit with an unknown voltage drop, how do you propose you measure it?

Just how many Amps and what wires are you guys running through these boats ? What else do you need connected on one leg of wire on a small vessel other than some running lights up front.

Voltage drop on What exactly .. the running lights? ( thats the only thing I can think of that would/Might require you to run the Same wires to multiple lights ).

I would think that the radio and other instruments would be on there own Leg of power. Bilge pump included.

I think a Test Probe light would get you further then anything that a simple Volt meter can do in a simple 12 volt leg system.

Visual inspection of connectors and wire connectors would be a better bet.

Also .. just because you get 12.7 volts at the battery .. does not mean you have the Amps anymore. You need to Load test the battery to see if it can put out the Amps.

Volts is not Amps .. Resistance is your friend when reading 12 Volt systems. There you can find your "crazy" stuff.

YD.
 
Joined
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2,906
Re: need a sticky/link on how to use a basic volt meter

don i was hoping for a link to the most basic problems we see not the weird ones we all enjoy

so i was thinking something like this

how to find a ampage draw that leaves the battery flat after a few weeks (title)
pic of battery with leads
pic of battery with pos lead removed
pic of meter set to amps
pic of meter with leads set in amp position (center most cheap meters)
pic of meter in line
text should read 0.0
text if the meter reads 0.0 turn on the stern light and the meter should read a few amps this confirms you have the meter installed correctly
text remove fuses until the meter reads 0.0 and you have found your problem


how to test the fuse panel for voltage (title)
pic of fuse panel
pic of meter set to dc volts
pic of leads on fuse and ground
text if the meter reports a - number check your leads are red to fuse black to ground
text if your meter does not read 0.0 see the checking battery voltage sticky to confirm the meter is set right if your meter is working correctly see the "testing for a broken ground sticky"

how to check a battery and alternator (title)
pic battery
pic volt meter set to dc volts
pic of meter on battery
text the voltage should be ???? if the voltage is less check the battery is charged. if the battery charger says that the battery is full take it to a autoparts store for testing
text remember the number from the battery test now start engine and measure the voltage the voltage should now be slightly higher confirming the alternator is working if the voltage exceeds ???? then shut off the motor as you have a problem with the regulator
text if the battery will run lights etc but will not start the engine ask the auto parts store to load test the battery to check it has available ampage to start a engine.

im not asking it to be in my words or my ideas or tommorrow just something that grows and we can link to with the very basic problems. i link to silvertips drawing all the time as there neat and easy for someone who can not understand line drawings and they seem more comfortable with a picture of a switch rather than the line drawn way the switch connects
 

Don S

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Re: need a sticky/link on how to use a basic volt meter

I figured this might be one.

how to find a ampage draw that leaves the battery flat after a few weeks (title)
pic of battery with leads
pic of battery with pos lead removed
pic of meter set to amps
pic of meter with leads set in amp position (center most cheap meters)
pic of meter in line
text should read 0.0
text if the meter reads 0.0 turn on the stern light and the meter should read a few amps this confirms you have the meter installed correctly
text remove fuses until the meter reads 0.0 and you have found your problem

So, put text to this picture to explain your points.

attachment.php
 

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Joined
Feb 17, 2012
Messages
2,906
Re: need a sticky/link on how to use a basic volt meter

Before anyone expends a lot of time and energy or risks re-inventing the wheel, here's an excellent open source compendium on electric circuits which includes details on the use of meters. This information spans from the basic to the detailed. In my experience as a college professor teaching apprentice electricians, I judge this to be a terrific reliable resource and it's free.
Check it out. - Grandad

http://openbookproject.net//electricCircuits/

http://openbookproject.net//electricCircuits/DC/DC_8.html#xtocid69540

they are great links grandad and the next mechanic they give me as a helper is going to be busy reading all of them by the time hes finnished reading them and has watched the 3 horror movies on flash hazard it might be safe to have him tag along to learn something.

but in all honesty if its friday and the bilge pump doesnt work and you plan fishing tommorrow do you

A- read up and learn how it works including magnetic field theory
B- ask someone else how to fix it
C- take a wild guess and just start replacing parts with out testing as you have no idea how to use a meter then move to option B
 
Joined
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Messages
2,906
Re: need a sticky/link on how to use a basic volt meter

I figured this might be one.



So, put text to this picture to explain your points.

attachment.php

im not good at writing don so give me a bit and i will try to write something thats realy simple and basic that someone with no experiance can understand.

i like the picture
 

Don S

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Re: need a sticky/link on how to use a basic volt meter

Plenty of time, so don't get in a hurry. I can also change the meter reading to 0.0 with no problem.
 

bruceb58

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Re: need a sticky/link on how to use a basic volt meter

Voltage drop on What exactly .. .
I can think of a few things:

1) Voltage drop across a coil.
2) Voltage drop across a ballast resistor.
3) Voltage drop from the battery to a starter to determine resistive connections or a starter consuming excess current.
4) Voltage drop from the battery to any number of destinations that go through connectors to determine a resistive connector.

This is just a few and that's just for measuring voltage drop.

Other things you need a multimeter for in a 12V DC system.

1) Measuring AC ripple of your alternator output due to bad diodes.
2) Measuring alternator output voltage.
3) Measuring coil primary and secondary resistance.
4) ....
 

bruceb58

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Re: need a sticky/link on how to use a basic volt meter

im not good at writing don so give me a bit and i will try to write something thats realy simple and basic that someone with no experiance can understand.

i like the picture

attachment.php


Of course that measurement would indicate a negative current. Need to reverse the leads.
 

Don S

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Re: need a sticky/link on how to use a basic volt meter

Of course that measurement would indicate a negative current. Need to reverse the leads.

I think it's right for checking Amperage, it is backwards if it were voltage.
 

Grandad

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Re: need a sticky/link on how to use a basic volt meter

Of course that measurement would indicate a negative current. Need to reverse the leads.
I think Don has it right. That's how I'd connect for a positive amp reading. - Grandad
 
Joined
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Messages
2,906
Re: need a sticky/link on how to use a basic volt meter

how to use a volt meter to test a battery that goes flat after 2 weeks

electricity is sometimes refered to like a liquid. a battery can be thought off as a bucket of electricity when everthing on the boat is turned off there is not meant to be any flow of electricity. the flow is so small that you will need a digitial volt meter (dvm) to read how much electricity is escaping leaving the battery empty

before connecting the meter make sure all switchs are turned off on the boat

remove the positive lead off the battery, turn the volt meter to the 10amp setting, connect the leads on the meter to the A and the common, connect the meter as shown in the picture.







the reading will show how much flow of electricity is leaving the battery. if the reading is 0.0 then turn on the anchor light and the reading should go up to 1 to 2 amps which proves the meter is working. if everthing is turned off and the meter does not read 0.0 then you will need to pull fuses until the meter goes to 0.0 the fuse you pulled to make the meter go to 0.0 will be the one thats draining the battery



what do you guys think to this.....hard to keep it short and not complicated yet not insulting
 

Don S

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Re: need a sticky/link on how to use a basic volt meter

Well Glenn, I felt ambitious this morning, here is one I put together on testing voltages up to the fuse panel in a boat.

http://forums.iboats.com/showthread.php?t=583456

You guys look at it and make sure I don't have something wrong in the pictures and/or the text or making something clearer.
 
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