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

[glenn property of pam]

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.

 

[Don S]

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

What people need to do is learn a little bit about electricity and how it works, not just how to use a meter. If you don't know where to check, knowing how to use the meter won't help.

Get a book like this.
http://www.amazon.com/Powerboaters-..._B001H6QTOM_1_2?ie=UTF8&qid=1350750561&sr=1-2

I actually bought that book (Kindel version) about a year ago just to see what it was about. Downloaded the kindel viewer for free and was looking at the book within minutes.

People without a basic knowledge of electricity is why boats have so many wiring problems.

 

[Silvertip]

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

Agreed -- if one does not know WHY you check resistance, WHY you check voltage, WHY you check current, WHEN it is appropriate to do these tests, or what the terms even mean, then knowing how to use the meter is of no value. Instructions normally come with the meter. But -- the long and short of this is:

VOLTAGE: A boat has a 12 volt DC electrical system. You set the meter to read DC volts and measure ACROSS the +12 volt and ground leads to verify a device or circuit has power applied to it. Trolling motors can have 12 volt, 24 volt, or 36 volt battery banks consisting of one, two or three 12 volt batteries in SERIES as applicable (example: 12 x 3 = 36 and 12 x 2 = 24). If you don't know the difference between parallel and series wiring then you should understand why knowing how to work the meter is of little or no value.

RESISTANCE: Resistance in a circuit is measured in OHMs. You set the meter to read RESISTANCE (Rx1, Rx10, Rx100, etc). You NEVER measure resistance on a powered circuit unless you want to fry the meter. The meter has it's own internal battery for resistance measuring purposes. You measure resistance of a fuel sending unit, temperature sender, trim sender, coils, and other devices. The resistance setting is also used to verify end-to-end "continuity" of a circuit. Unless you know what value to expect (listed in the product literature or service manuals) you have no idea what is OK and not OK. You must also disconnect the circuit under test from anything else to ensure you are measuring ONLY the device of interest.

CURRENT: The current (amps) flowing in a circuit is measured with the AMPS function. On most handheld meters current is limited to about 10 amps so you don't use that function to test starter current draw. Current is measured with the meter in SERIES with the circuit under test. You need to know the "expected" current draw in that circuit to conclude whether or not the value you are reading is OK or not OK.

Some winter day when it about 30 below zero I will create a pictorial of how these three measurements are made using real parts.

 

[Yacht Dr.]

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

Agreed -- if one does not know WHY you check resistance, WHY you check voltage, WHY you check current, WHEN it is appropriate to do these tests, or what the terms even mean, then knowing how to use the meter is of no value. Instructions normally come with the meter. But -- the long and short of this is:

VOLTAGE: A boat has a 12 volt DC electrical system. You set the meter to read DC volts and measure ACROSS the +12 volt and ground leads to verify a device or circuit has power applied to it. Trolling motors can have 12 volt, 24 volt, or 36 volt battery banks consisting of one, two or three 12 volt batteries in SERIES as applicable (example: 12 x 3 = 36 and 12 x 2 = 24). If you don't know the difference between parallel and series wiring then you should understand why knowing how to work the meter is of little or no value.

Yes .. but to those that have a 50A or 2 30A plugs dont apply to your 12 volt DC system...

I agree that some kind of sticky should be applied in the "how to" section. Typically Dont do it yourself when your talking about chargers and stuff.

Same with fuel lines..

YD.

 

[glenn property of pam]

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

Yes .. but to those that have a 50A or 2 30A plugs dont apply to your 12 volt DC system...

I agree that some kind of sticky should be applied in the "how to" section. Typically Dont do it yourself when your talking about chargers and stuff.

Same with fuel lines..

YD.

way over my head......no idea what you are on about.

silvertips im thinking more of a simple step by step rather than down to basics type of thing. if someone has a battery going flat over 2 weeks then we all surgest using a amp meter to test for something that is drawing current. i was looking more for a basic post that i can link to with basic step by step instructions
example
to test for amp loss when everything is turned off ..... pic of battery with leads.... pic of volt meter and the setting for amps...pic of the lead set up on the battery.....pic of the amp meter being put in line.....pic of fuse panels with fuse being pulled until the amps drop to zero..
it would be nice to be able to link to a stick say post..http://forums.iboats.com/showthread.php?t=583119 post #5 rather than having to try to explain everything from scratch.

don i agree its better to know how it works rather than magic in a box but this isnt a pefect world and people want the ans now. im sure i could have found a book on how to rebuild my boat and how to do fiberglass and with in 6 months i could have been a paper expert on the subject but i was lazy and to much in a hurry so i asked and used the forum experiance, links to projects, how to's to learn the basics then asked when i ran into problems or needed something else

 

[NYBo]

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

Yes .. but to those that have a 50A or 2 30A plugs dont apply to your 12 volt DC system...

way over my head......no idea what you are on about.

He's referring to AC shorepower systems.

 

[Silvertip]

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

It is not practical to create a "How To" sticky for use of a VOM for the simple reason there are too many scenarios. Do a forum search on FUEL GAUGE PROBLEM for example. There are roughly 33 responses to just those three key words. You cannot get people to do a forum search on any issue or there would be a lot fewer fuel gauge questions. Then try "Gauges Don't Work". Another topic which has been discussed time and time again. Then there is trolling motor wiring, starter malfunctions, bilge pumps, live well pumps and timers. You cannot possibly cover all of these step by step. You can cover "How to measure voltage, resistance and current" with pictures but you need to have at least a reasonable grasp of low voltage circuit theory for those tests are meaningless. There are lots of books that go into this so there is no reason, in my view, to reinvent the wheel. If people are smart enough to search for and find this forum they should be smart enough to find basic electricity texts on-line. There is nothing simpler than boat trailer wiring yet folks really get wrapped around the axle trying to solve those issues. There are only four wires to deal with and one is ground. Troubleshooting, whether mechanical or electrical requires at least some analytical ability. Some people have it and some don't Sorry to be a stick in the mud here but there is no reason we need to rewrite basic electronic texts. Although I didn't do an on-line search for "How to Use a Multitester, or How to use a VOM" I'll bet there are dozens of responses.

As for AC (shore power) wiring and engine electrical system troubleshooting, the novice can get hurt badly by poking around in an uniformed manner. Engine electrical troubleshooting is always covered in the factory service manual for whatever engine you are working on.

I did a Google search using the keywords "How to Use a Digital VOM" and there are lots of tutorials including text and videos. The best I could suggest for this forum is to show a Sticky but in that sticky provide Keywords for a Google search that takes the reader to those sites.

 

[matt167]

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

did you know that if you hold the neutral leg and ground leg of a 110v system at the same time, with only the switch off but not breaker, you will start buzzing? learned that the hard way.. If you ask someone to kill a breaker. CHECK IT ANYWAY.. And it wasn't a boat. I was wiring/ installing an outside light..

I'll see what I can do for a simple diagram. I have to boot into Windows so I can use the program I have.

 

[Don S]

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

CLICK HERE, then scroll down and look at the related items.

 

[Don S]

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

did you know that if you hold the neutral leg and ground leg of a 110v system at the same time, with only the switch off but not breaker, you will start buzzing? learned that the hard way.. If you ask someone to kill a breaker. CHECK IT ANYWAY.. And it wasn't a boat. I was wiring/ installing an outside light..

I'll see what I can do for a simple diagram. I have to boot into Windows so I can use the program I have.

We are discussing basic 12volt boat electical systems here, not 110V house wiring :facepalm:

 

[glenn property of pam]

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

must admit i do like the links dons does...lol. ac and dc are diffrent so yes they can search the web and if they search under dc maybe that will give them the basics of what the meter does but then they will still need to know what to test and what results to expect but then again im sure they could search for the ans to that.

the search on this site is a little iffy and i find that google or yahoo can do a better search that links back to this forum

 

[Don S]

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

must admit i do like the links dons does...lol.

Just go to http://lmgtfy.com/ and type in what you want to search for, then use the copy item, then preview.

 

[matt167]

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

We are discussing basic 12volt boat electical systems here, not 110V house wiring :facepalm:

Lol I know but 110v Shore power was mentioned.. It's just 1 story I usually mention when how to electrical gets mentioned..

 

[matt167]

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

must admit i do like the links dons does...lol. ac and dc are diffrent so yes they can search the web and if they search under dc maybe that will give them the basics of what the meter does but then they will still need to know what to test and what results to expect but then again im sure they could search for the ans to that.

the search on this site is a little iffy and i find that google or yahoo can do a better search that links back to this forum

Just type " Site: forums.iboats.com ________" and you will only pull up Iboats forums searches. Works with any website also.

For instance, to pull up starcraft topics, just type "site:forums.iboats.com Starcraft"

 

[bruceb58]

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

Putting up a sticky on how to use a VOM and expect someone to troubleshoot electrical systems is equivalent of putting up a sticky on how to use a wrench and expect them to be able to fix an engine.

As an example, I see many posts on here that use a VOM on ohms and try to measure tenths of ohms to diagnose a voltage drop problem. Just because you know how to use various functions of a tool means nothing if you don't know when to use it.

If you really want to just learn how to use a VOM, there is a ton of info online.

 

[glenn property of pam]

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

Just go to http://lmgtfy.com/ and type in what you want to search for, then use the copy item, then preview.

thanks don

 

[Thalasso]

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

CLICK HERE, then scroll down and look at the related items.

That is so cool. How do you do that

 

[glenn property of pam]

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

ive had a change of heart.......im now going with don on post #2. i guess since ive been doing electrical most of my life it never realy dawned on me just how hard some people find it.

 

[Yacht Dr.]

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

12V is easy .. GPOP . ..

But to suggest how to use a Voltmeter/ampmeter is kinda like putting kindling on a fire.

You dont really need a voltmeter in a 12 volt dedicated sytstem ..its when you start putting shore power (110 or 220 (30amp or 50amp) to it that might complicate the system.

DC and AC is two different components .. and to switch AC to DC is another monster that some might not want to go into.

As soon as you put that power plug from the dock .. your in for a different system.

But if your just 12V then I guess its fine..

YD.

 

[Don S]

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

I suspect that since 99% of the threads started in this forum are on 12V systems and small boats that that is what Glenn was referring to and not anything about AC.