Amp vs Volt Gauge

Oaf

Member
The amp gauge on my 650 has a bad seal and I want to replace it before I put the loader back on.

If I decided to install a volt gauge instead of replacing the amp gauge, can I just hook the wires up the same way on the two posts or is special wiring needed?

The previous 12V conversion would require a 12V volt gauge, but is there a difference between 6V and 12V amp gauges?

Thanks.
 
Amp gauge and volt gauge work different so to use a volt gauge you would have to rewire it some but to go back with an amp gauge it is a simple remove and install. Amp gauge reads charging system out put while a volt gauge reads battery volts and or charging volts
 
Ammeters and Voltmeters are wired differently.

Maybe a diagram will help, or maybe it will confuse.

VoltandAmmeter.jpg


For a voltmeter, I would hook up the + side of the voltmeter to the switched side of the ignition switch and the - side to a chassis ground. Make sure the + side of the meter is on the switched side of the ignition switch or the meter will stay on with the tractor off and slowly drain the battery.

Hope this makes sense
 
You really want to reinstall an amperage gauge. NAPA has numerous varieties.

Batteries are charged by current flowing into them to move the chemicals from solution to the plates. You can easily watch the rate of charge from say 20 amperes to just a trickle, as you can watch the rate of discharge.

Before the advent of digital voltmeters, voltmeters were more or less useless as a volt or a few tenths would mean the difference between charged and needing it and the resolution on analog meters (those with needles), especially the lower priced ones, couldn't show you that difference.

Trust me, reinstall an ammeter. Plus side is you have no rewiring to do; just get one with adequate ranges, undo the wires from the old and connect to the new.

Mark
 
Oaf,
I have a 1950 IH C and a Jubilee, both are 12v conversions. You can use a diode or an idiot light to fire up the alternator. I like the idiot light. Before I start the tractor the light is on, telling me the alternator is getting a wake up call and my fuses are good. When the light goes off, it tells me the alternator is charging. The amount of charge really isn't that important. I do like the ammeter over the voltmeter. The idiot light really eliminates the need for either. I do have many idiot lights on the workbench, because they can go bad.
George
 
or, and your diagram proves it, ampere gauges are
wired in the circuit and voltmeters are wired across
the circuit.
 
Thanks one and all!

I now see the difference and will plop in another ammeter just to save the trouble of fooling with it.
 
I just completely rewired my NAA to 12 volt. Changed to a volt meter because the ammeter was only rated for 30 amps and the alternator was 61 amp and I just prefer the volt meter (don't know why). When the alternator is charging the battery it shows just over 15 volts and then drops to 14 when normal. If you are going to stay with a ammeter I would go with a 60 amp meter if you are running an alternator.
 
yep.. you will have to do minor rewireing toinstall a volt meter.

wire the 2 wires together at the old ammeter.

wire a wire from the switched side of key switch to + of voltmeter.. and - of voltmeter to chassis.

key on = voltmeter reading.

me personaly? I prefer an ammeter.. it shows you the 'health' of your electrical system.. not some ominous volt measurement that MAY be meaningless...
 
No need to go to a 60 amp gauge just because you have an alternator that is rated at 60 amp. A 30 amp one works just fine since in all likely hood the alternator on a tractor will NEVER put out the full 60 amps and if it does then you have a short and that will in turn most likely fry the alternator.
So now your handle say you live in Missouri where are you at. Me I am at the lake of the Ozarks. Former Navy Electronics technician by the way
 
(quoted from post at 19:23:29 01/21/13) No need to go to a 60 amp gauge just because you have an alternator that is rated at 60 amp. A 30 amp one works just fine since in all likely hood the alternator on a tractor will NEVER put out the full 60 amps and if it does then you have a short and that will in turn most likely fry the alternator.
So now your handle say you live in Missouri where are you at. Me I am at the lake of the Ozarks. Former Navy Electronics technician by the way

I just like everything in a system to match, just me I guess.

My handle has been in MO, been here in Troy, Mo just NW of St. Louis since 2008. Prior to 2008 I was in Wisconsin. My dad is just north of Branson, he's been there for about 30 years.
 
As far as electronically matching on an amp gauge pretty much no need to do so since almost never will see full amps and many times a gauge that is to high rated will not show you what you really need to know.
I know about where you are at and also where you dad is at. Been here Camdenton, the Lake of the Ozarks since I got out of the navy in July of 1980 so in July of this year it will be 33 years of living here
 
An alternator can indeed put out its max output when the battery is low and the engine is first fired off. Full output does not mean that there is a short somewhere.

Also, full output would not fry the alternator, as they are self-current limiting. An alternator rated at 60 amps will put out approximately 60 amps and no more if the situation calls for it.
 
To argue with you would be pointless as your answer is also but hey have your own opinion. I know what I have said is right but oh well just been doing this for decades and 30 amp gauges have worked well for decades
 

Go Voltmeter its all you will generally need in daily operation of your tractor,,, a amp meter is only needed when you get into serious diagnostics...
 
Yep McDaniel's lawn mower shop is next door to it. Across the street to the right is Camdenton gun shop. Then if you go behind that white pick up the tail of it point at the court house. That sits at the junction of Hwy 5 and Hwy 54 About 7 miles from my place. I think in the 32 plus years I have lived here I have been in that place less then 5 times
 
If you know what you said is "right", then you need to think long and hard about what you say here on this board. 3 out of 4 statements you made about alternators are flat out WRONG!

Leading people down the wrong path is never the right thing to do.

Go ahead and prove me wrong if I said something incorrect.

BTW, I never said a 30 amp gauge would not work for him.
 

I think it is nice to see the areas that people come from.

For example...here is close to where I live:

14000.jpg
 
Does not matter you did this the other day wit h JMOR now with me. I will not argue like a little kid I would not have even seen your answer had it not come up on the top and will not see if you answer me again so drop it
 
Can not say I know where that is but looks like it could well be close to this area but then a river or lake and a bridge can be most any where LOL
 
Yes, it does matter. When you respond to a post, there are people looking for accurate information. You and JMOR have been misleading and/or factually incorrect, and that's being charitable.

Why don't you debate like an adult? Little kids argue to prove who is right. Adults argue to get the correct answer, which is really what is important here. Are you afraid to debate?

JMOR and I debated. I finally conceded that he was technically correct in order to satisfy a wordsmith, but that his description of valve action was very misleading for a novice. That was my ONLY point.

Now, we are supposed to accept everything you say as GOSPEL?
 
As I see it, the biggest problem with running the original ammeter on an alternator system is voltage drop through the original wiring. If I was rewiring a tractor for a 12 volt conversion, I'd go with a voltmeter because it's simpler to wire than an ammeter and allows the alternator output to be connected directly to the battery with heavy gauge wire. Which is the main reason ammeters disappeared from passenger vehicles forty years ago: high-capacity alternators required a remote shunt for the ammeter, which adds cost and complexity. A voltmeter requires a single small-gauge wire to a source of 12 volts and a ground.

As a diagnostic tool, I prefer a voltmeter. A slight discharge is difficult to see on a ammeter, but is obvious with a voltmeter. It's difficult to detect a failed diode or regulator with an ammeter.
 

Whut he said,,,, every time I have pinned a amp meter lubber down they seam to get tong-tied answering a simple diagnostic question.... I will leave my amp-meter in my box till I need it but the first thing I will tote with me to diagnosis a no crank no start is a voltmeter...
 
They both have their place. I mostly use a voltmeter for diagnostics. When you know how to read the nuances of the meter you're using it generally tells you about all you need to know.
As far as I'm concerned, in terms of a charge reference on a machine with an alt... the old idiot light is as good as any.
An ammeter can also give you a lot of good info tho.... very quickly show you a discharge situation if it's wired correctly, belt slip, no charge, etc. IF you know wht you're looking at.
The main thing I use an ammeter for (current clamp) is checking starter draw. For that, it's indespensible.

Rod
 
On that tractor I'd probably just replace the ammeter... for the simple reason that it's easy and it keeps it original... and for the most part it gives you as much info as you need anyway.
If you wanted to use a voltmeter there isn't much rewiring to do. Just nip the ring ends from the wires that went to the ammeter and join them together with a butt connector. Then take a switched power source off the key to feed the voltmeter along with a ground for the other side of it. Done.
If you had a ground disconnect on the tractor... all I'd do is hook the two ring terminals on the present wire to the pos stud on the voltmeter, then ground the other side of the meter and call it good. A VM will discharge the battery if it remains connected when the tractor is not in use...

Rod
 

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