Multimeter question

[RMS]

Rms, Instead of just telling you which scale to use….here’s some basic helpful info that might save you from blowing too many fuses on your meters during your learning curve. Especially since your OTT handle is RMS, which in the electrical measurement department stands for “Root Mean Square”.

V DC = Volts Direct Current
V AC – Volts Alternating Current
mA DC = milli amps (1/1000 amp) Direct Current (not to useful for general tractor troubleshooting but good for blowing meter fuses!)
BATT = checking common AA, D, C, 9v flashlight batteries, etc.
Ohm x 1K = Ohms resistance x 1000
Ohm ADJ = For adjusting the ohm reading to “Zero” when you short the test leads together.

Example for V DC: The settings of 10, 50, 250, are the maximum full scale reading in volts that can be safely read in each of those selections. If you were expecting to read 120 Volts DC you would select the 250 VDC setting because 120 volts falls within that range. Your tractor battery is in the 12 to 13 volts DC so you would select the 50 VDC setting to check your tractor battery voltage.

If you’re unsure of a voltage that you want to check, select the highest range first. Then when you see which range the voltage would fall into….then select the proper lower range for better resolution of the reading.

Note the meter scales are laid out (top to bottom) OHMS, Volts (250, 50, 10) etc.
Each meter scale corresponds to the respective setting you have chosen on your meter.
If you select the 50 VDC range to read your battery voltage, you will be using the middle scale (Volts) that has the 50 at the full scale range on the right side of the meter face.

If you are measuring ohms. You would be using the top scale. And since the meter shown has the ohm scale x 1K…..that means you would multiply the reading by 1000 to get the actual resistance value.

Selecting too low of a scale on this meter you will likely “Peg” the needle to the far right and may damage the meter movement and may also blow a fuse. That’s why if the value to be measured is unknown, you start with the highest scale and work your way down to the proper scale.

On your new electronic meter, if the value being measured is “out of range” (improper scale selected) you will most likely see an “OL” or other indication on your LED display. Depending on the meter, it might be more forgiving of making mistakes. You may still blow an internal meter fuse, but they’re easily replaced.

As an example of choosing the right scale and seeing the better resolution: select the 250 VDC scale and read your tractor battery voltage. (remember to read it on the 250 FS (Full Scale) range (top scale).

Then select the 50 VDC range and read the voltage on the 50 FS (Full Scale) range. This will give you a much better (more accurate) resolution.

Do Not select the 10 VDC range as that is usually below your battery voltage. You will peg the needle to the far right of the movement and possibly damage the movement if your battery is fully charged.

However, if the previous scales show that your battery is bad or discharged to a lower level than 10 Volts….then you can safely use this scale to more accurately read any voltage below 10 volts.

As a new user of a multi meter, you should not try to measure resistance with your meter when the battery voltage is present in the circuit. Especially with this analog meter (needle movement vs the LED meter). Until you become more familiar with taking circuit readings with your meter, you’d want to measure resistance with the device completely disconnected from the circuitry.

These are just some very basic “how to’s” in helping you get started in understanding those different settings. It would be a shame to damage that nice little vintage analog meter!!

Hope it helps a little!!
David

Thankyou very much! I'm more comfortable dealing with water in pipes vs electrons in wires. This electron sh@@ is all black box magic to me.

 

[wp6529]

I'll note that the better DMMs often have a moving pointer graph to provide something similar to the old analog needle movement that can be helpful in visualizing some conditions without dragging out a 'scope. Then of course there are also some rather nice inexpensive table oscilloscopes available these days.

 

[fried1765]

Nice old Sears multi-meter. Fairly accurate. You could sell it on Ebay as a vintage tool. I have one that I bought from Radio Shack ~1983. View attachment 120876

I have one of those somewhere.
Only use my Fluke meter now!

 

[DaveFromMi]

Thankyou very much! I'm more comfortable dealing with water in pipes vs electrons in wires. This electron sh@@ is all black box magic to me.

The math & models for water flow and electron flow are similar.

 

[GreensvilleJay]

I'd dock you 10 points for the switch being closed. You drained the battery !

 

[Russell King]

Rms, Instead of just telling you which scale to use….here’s some basic helpful info that might save you from blowing too many fuses on your meters during your learning curve. Especially since your OTT handle is RMS, which in the electrical measurement department stands for “Root Mean Square”.

Hope it helps a little!!
David

@bird dogger thank you for your detailed explanation.

I also noticed his RMS user name and his fear of electrons to be confounding! Assuming that RMS is initials from three names they should have been an electrical engineer.

But I have a similar problem with my first name initial and last name (R. King) ( think arcing when you say it). I never noticed that until someone thought I was suspicious signing into a visitor log book and they had some electrical problems that day. I became an engineer but not electrical so I missed using that signature on schematic drawings.

 

[bird dogger]

@bird dogger thank you for your detailed explanation.

I also noticed his RMS user name and his fear of electrons to be confounding! Assuming that RMS is initials from three names they should have been an electrical engineer.

But I have a similar problem with my first name initial and last name (R. King) ( think arcing when you say it). I never noticed that until someone thought I was suspicious signing into a visitor log book and they had some electrical problems that day. I became an engineer but not electrical so I missed using that signature on schematic drawings.

Russell,
Yes, it jumped out at me right away that someone legitimately asking for some basic help in using a multimeter would have initials of "RMS". Nothing more than an unusual and rare coincidence!

Same with your initials, if by chance you would have went the route of an EE (electrical engineer).
I was an electrical technician (protective relay technician) and with your initials on the prints.....I'm sure we would have given you friendly grief had we found any errors on your schematic drawings. LOL!
David

 

[bird dogger]

Thankyou very much! I'm more comfortable dealing with water in pipes vs electrons in wires. This electron sh@@ is all black box magic to me.

RMS, your welcome! As long as you start out with understanding the basic settings of your meter and how they're used you'll avoid letting the "magic smoke" out of the devices you're working on....or your meter itself.....hopefully.

But sometimes we all get in a hurry & without thinking something through, then "Poof"..... the fuse in your meter is blown. It pays to have a few spares on hand just for those occasions.

If you google "how to use a multimeter", "Basic Multimeter Testing", etc., you'll find some good tutorials that will explain the basics. There are some good youtube videos as well.

You can also google "How to test (?) with a multimeter" and get some detailed results for that particular situation as well.

Remember to double check that your meter's selection is correct for your measurement before you apply the probes to any teminals and you'll soon be on your way!

Don't be bashful about asking questions here as well. Someone will surely help you out!

David

 

[RMS]

RMS, your welcome! As long as you start out with understanding the basic settings of your meter and how they're used you'll avoid letting the "magic smoke" out of the devices you're working on....or your meter itself.....hopefully.

But sometimes we all get in a hurry & without thinking something through, then "Poof"..... the fuse in your meter is blown. It pays to have a few spares on hand just for those occasions.

If you google "how to use a multimeter", "Basic Multimeter Testing", etc., you'll find some good tutorials that will explain the basics. There are some good youtube videos as well.

You can also google "How to test (?) with a multimeter" and get some detailed results for that particular situation as well.

Remember to double check that your meter's selection is correct for your measurement before you apply the probes to any teminals and you'll soon be on your way!

Don't be bashful about asking questions here as well. Someone will surely help you out!

David

Thanks for all of the help. I'm sure that there are others learning from this too.
As a side note, RMS are my initials. Never been good at coming up with usernames so that seems to be my go-to. In my younger years I was a pipe-fitter, hence better with pipes and water.

 

[bird dogger]

Thanks for all of the help. I'm sure that there are others learning from this too.
As a side note, RMS are my initials. Never been good at coming up with usernames so that seems to be my go-to. In my younger years I was a pipe-fitter, hence better with pipes and water.

Here's a nice beginner's tutorial with pics, descriptions, examples, etc. The meter used is very much like yours....but with some additional features and extended ranges in the volt and amp settings.

How to Use a Multimeter - The Home Depot

 

[RMS]

Just as a follow-up. I did purchase a digital multi-meter and saw that once charged the battery had a little over 12v. I also had 14+v when running.
The dealer was picking it up to install rear hydraulics and I asked them to load test it while it was there. I mentioned it to the guy who came to pick it up and he immediatly looked at the diverter switch for my snowblower chute and checked to see how it was powered.
Turns out it was always energized and he said that they tend to hang up and constantly draw power. While he had it in the shop he rewired to only be energized when the key is on.
He said the battery appears to be good and is holding a charge.

 

[Runs With Scissors]

Just as a follow-up. I did purchase a digital multi-meter and saw that once charged the battery had a little over 12v. I also had 14+v when running.
The dealer was picking it up to install rear hydraulics and I asked them to load test it while it was there. I mentioned it to the guy who came to pick it up and he immediatly looked at the diverter switch for my snowblower chute and checked to see how it was powered.
Turns out it was always energized and he said that they tend to hang up and constantly draw power. While he had it in the shop he rewired to only be energized when the key is on.
He said the battery appears to be good and is holding a charge.

Thanks for the follow up.


Glad you got it worked out, and just an FYI (although I'm sure you already Googled it) , the 14 volts while running indicates a working charging system.

Knowing how to use a meter opens up a whole new world in regard to troubleshooting.

 

[GreensvilleJay]

re: the 14 volts while running indicates a working charging system.

yes, 'working' but not necessarily properly. The alternator may only be supplying an amp or two, not the 10-15 amps it's designed for, Sadly most machines today don't have ammeters in them which do show IF the correct charge is going into the battery.

 

[jaxs]

Thanks for the follow up.


Glad you got it worked out, and just an FYI (although I'm sure you already Googled it) , the 14 volts while running indicates a working charging system.

Knowing how to use a meter opens up a whole new world in regard to troubleshooting.

re: the 14 volts while running indicates a working charging system.

yes, 'working' but not necessarily properly. The alternator may only be supplying an amp or two, not the 10-15 amps it's designed for, Sadly most machines today don't have ammeters in them which do show IF the correct charge is going into the battery.

Well alrighty ,seeing as how we have the can of worms open we may as well cuss and discuss the little fellers .
In the absence of more tools and limited amp capability of meter ,might this help guesstimate alternator is indeed supplying more than 1 amp? With battery charged to 12.5v or more,note voltage to second decimal w & wo engine running then turn lights on.while engine is at fast idle. Modern lights pull 5-8 amps ,older lights about 2x as much. If volts don't fall the alternator is putting out more than a couple amps and should do fine unless heavier loads are added. After one is comfortable with their meter, they can make above test a liitle more precise by using amp feature on meter to test each light or combo NOT EXCEEDING meter capability. Add those up to arrive at total load.
If someone sees need to demonstrate prowess with ohm's law do us students a favor by not delving too deep before we can at least get our feet wet. I have to say that because I've seen novices give up what appears imposable to comprehend with amount of effort they are ready to put forth. Many would enjoy mastering ohm's law to up their game but that deserves it's own thread.

 

[Runs With Scissors]

re: the 14 volts while running indicates a working charging system.

yes, 'working' but not necessarily properly. The alternator may only be supplying an amp or two, not the 10-15 amps it's designed for, Sadly most machines today don't have ammeters in them which do show IF the correct charge is going into the battery.

True. I have no idea what his alternator should be producing and I generally don't take the time to find out.

So in situations where I am unsure/suspect of an alternator, I usually pull it and take it to my local rebuild guy to have it tested.

Here is how it usually goes:

I walk in and there is a guy there lighting his 26th Marlboro of the day, under the sign that says "No Smoking" while reading a copy of Barely Legal . (oh, and if it is even close to closing time, he is drinking a beer)

Jed: What'cha need?

Paul trying not to get fleas
from the mange ridden dog
that is licking himself in the middle of the floor: Can you test this for me?

Jed: BOBBY!!!! come test this, I'm busy......(goes back to reading "the articles" in Barely Legal)

Bobby, walks up, as he puts his cigarette out on the floor, and grabs the alternator. Then he walks into the back room, some noise is made, and 2 minutes later he walks out with another 1/2 gone Marlboro hanging from his lips and says either.......

1. Its good....and hands it back to me.

or

2. It's dead.....It'll be 80 bucks and ready by tomorrow if you want....


In the end, I can't recall ever using a multimeter to actually "test" an alternator and have no idea if its even possible. I only use it as a "indicator" before I yank it.

Much like "load testing" a battery Vs. Seeing if it has 12+ volts.

 

[fried1765]

True. I have no idea what his alternator should be producing and I generally don't take the time to find out.

So in situations where I am unsure/suspect of an alternator, I usually pull it and take it to my local rebuild guy to have it tested.

Here is how it usually goes:

I walk in and there is a guy there lighting his 26th Marlboro of the day, under the sign that says "No Smoking" while reading a copy of Barely Legal . (oh, and if it is even close to closing time, he is drinking a beer)

Jed: What'cha need?

Paul trying not to get fleas
from the mange ridden dog
that is licking himself in the middle of the floor: Can you test this for me?

Jed: BOBBY!!!! come test this, I'm busy......(goes back to reading "the articles" in Barely Legal)

Bobby, walks up, as he puts his cigarette out on the floor, and grabs the alternator. Then he walks into the back room, some noise is made, and 2 minutes later he walks out with another 1/2 gone Marlboro hanging from his lips and says either.......

1. Its good....and hands it back to me.

or

2. It's dead.....It'll be 80 bucks and ready by tomorrow if you want....


In the end, I can't recall ever using a multimeter to actually "test" an alternator and have no idea if its even possible. I only use it as a "indicator" before I yank it.

Much like "load testing" a battery Vs. Seeing if it has 12+ volts.

Load testing a battery is simple.
Battery need not be removed.
Just need to buy a (cheap) $30 carbon pile battery load tester.

 

[Tractor Gal]

When my old 6v battery was tested as good at Batteries Plus but it really wasn't good, I had thought about getting a load tester. The thought never went to action. Reading this thread has renewed my interest. In looking on ebay, there are TONS of these things...cheap. That gives me pause. Cheap stuff is rarely good and, believe me, I've bought plenty! So fried1865 references a "$30 carbon pile battery load tester." What in the world is that and how to find one.

Tractor Gal

PS Just went back to ebay and entered carbon pile load tester. Voile, there they are! Thanks for answering my own question! Maybe it will help someone else.

 

[Runs With Scissors]

When my old 6v battery was tested as good at Batteries Plus but it really wasn't good, I had thought about getting a load tester. The thought never went to action. Reading this thread has renewed my interest. In looking on ebay, there are TONS of these things...cheap. That gives me pause. Cheap stuff is rarely good and, believe me, I've bought plenty! So fried1865 references a "$30 carbon pile battery load tester." What in the world is that and how to find one.

Tractor Gal

PS Just went back to ebay and entered carbon pile load tester. Voile, there they are! Thanks for answering my own question! Maybe it will help someone else.

TG,

I think the "carbon pile" refers to 'old school " resistors made of carbon that generate heat when current goes through them.

That's why they have heat guards on them because they "heat up" as you use them.

Like this one.

https://www.amazon.com/Neiko-40510A-Volt-Battery-Tester/dp/B07B3R4TS6/ref=sr_1_2_sspa?crid=3CCVA5E60J8VM&keywords=battery+load+tester&qid=1706800650&sprefix=battery+load+tester,aps,90&sr=8-2-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&th=1


Edit: Also they are probably "cheap" because they have been around since Jesus was a Corporal.

 

[Tractor Gal]

TG,

I think the "carbon pile" refers to 'old school " resistors made of carbon that generate heat when current goes through them.

That's why they have heat guards on them because they "heat up" as you use them.

Like this one.

https://www.amazon.com/Neiko-40510A-Volt-Battery-Tester/dp/B07B3R4TS6/ref=sr_1_2_sspa?crid=3CCVA5E60J8VM&keywords=battery+load+tester&qid=1706800650&sprefix=battery+load+tester,aps,90&sr=8-2-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&th=1


Edit: Also they are probably "cheap" because they have been around since Jesus was a Corporal.

So, Runs With Scissors, does it do what the DIY needs? I wouldn't need fancy and have never criticized "old" because I are one! The digital display seems nice but the needle graphs would provide more info, I would think. The one you linked at Amazon is also on ebay for $10+ less. I like to save where I can for the same item.

TG

 

[Runs With Scissors]

So, Runs With Scissors, does it do what the DIY needs? I wouldn't need fancy and have never criticized "old" because I are one! The digital display seems nice but the needle graphs would provide more info, I would think. The one you linked at Amazon is also on ebay for $10+ less. I like to save where I can for the same item.

TG

That style should work just fine for a DIY'r.

I have no idea how well that particular model works though.

It looks like it gets so/so reviews.

The ones I used back in the late 80's /early 90s took a hell of a lot of abuse, I can tell you that much.