Jubilee alternator amps

Slong1958

New User
Hey guys I've been working on a friends tractor that has been changed over to a 12volt system and it also has no points it's been changed to
solid state ign and I'm needing to know how many amps should the amp gauge be showing. With the tractor running a 1600 rpms it's shows
about 20 amps. The alternator is putting out 14.62 volts if that helps.
Thanks
 
I actually had an extra 2 wire AC Delco that we went through today. Its output is around 30 amps. Hope it helps.
 
Also, We removed the amp gauge and installed a voltage gauge. The amp readings were a lot more important on a 6v systems as they needed a ton.
 
The amount of charge depends on the condition of the battery.
If the battery is fully charged, it should read nearly zero amps.
If you just started it after sitting, 20 amps would be normal for
a while, then it should settle down to near zero once charged.
All assuming the battery is good.
 
The battery is new but the tractor hasn't run much so I put the charger on it last night. Thanks for the help.
 
20a for a while on a not fully charged battery is normal. if output stays high, check your batteries specific gravity.
 
Do not worry about the amps, if the voltage is fine, the amps are doing their job.

My dad said, "take care of the voltage and the amps take care of themselves".
 
Except when it's not true....

With a modern hi power alternator, and a battery with a marginal cell , you can have normal system charge voltage.. say.. 14.4v.. but be pumping 10-20+ amps becuase of that marginal cell. it's not a short.. and the alt can keep up.. but it's sure not normal. That's one of those things a volt meter can't tell you, that an ammeter can.

You can have a marginal battery that has a bad cell, start up in the morning, have that alt cook that battery while you are mowing.. volts will be fine, and as long as the load isn't over the alts rated capacity, it will make em. you could be pumping 35-55 amps into a battery till it runs bone dry from boiling, then virtually becomes an 'OPEN'.. your voltage gage will still say 14.4v and your lamps and electrics will work.. but when you stop at lunch or to get fuel, you might not even get a click! An ammeter would have told you something was very wrong, while the volt meter just told you one thing... voltage.

the charge rate that amp meter displays is telling you multiple things about your charge system, you just have to be smart enough to understand it's language. Volt meter tells you a single thing... voltage.. and in the big scheme of things, voltage means less than amps. Want proof? go get 2 6v lantern batteries and wire them in series and check with a meter.. that will say a little over 12v.. just about the same as your car battery.

which one will start you car? that's right.. the one with the amps...
 
Soundguy,
Not wanting to start something, BUT.
When you turn the key on and you have a battery with a bad/weak cell, that VOLT meter will show you that the battery is weak. Your Amp meter shows normal.
Just saying.
Keith
 
for someone that is afraid to turn the key and hit the button without asking permission from the volt meter.. maybee..

You don't need the volt gauge to tell you that you have a bad or week battery.. your starter will tell you. That's part of paying attention to your machine, same with the amp gauge.

If I hit the start button on my tractor and the starter is spinning 20% slower than normal, I don't need to look at some volt meter to tell me the battery is low... maybee some do I guess.

Once you are started, you can then look at your ammeter. if the charge tapers off... your battery was low but probably ok.. ( IE.. you used the lights for a project for 30 minutes after shutoff and the battery drained a bit ). On the other hand, if the charge doesn't taper off, now you know that the high continous charge rate, coupled with the slower starter.. that you very likely have a problem with the battery. That very special and highly prized volt meter won't tell you that.

Again.. tools like this do rely on the user having some basic understanding of the world around him. Mindless sheep who just hop on press buttons and go won't benefit much or any from an ammeter.. and the volt meter just makes them feel special.. because they have a volt meter.. and that's the right thing to have.. right?

besides.. that last volt meter I say at orilies.. the cheap one.. that lots of tractor owners probably reach for has 3 voltages listed. 8, 12 and 18 usually.. though the middle number I have seen from 12-15 depending on what chinese company made the gauge. the rest of the gauge is in, sometimes graded, sometimes non graded hash marks that may or may not add up to voltage increments you can figure out. The last one of these I bought vibrated so badly, because it was a cheap undampened meter.. that you really couldn't tell if the needle was on 10 or 14 volts while driving thru a pasture cutting grass.

I'm trying to figure out how a meter that's hard to figure out a voltage helps anyone... if you can't tell if you are 10 or 14.. then you may be discharging, or may be charging. Also.. keep in mind my original post.. volts matter a little, amps matter alot. you can take a battery and deplete it past the point it will turn a starter, and still read 12v on it, hit the key and have it drop right on down to near nothing. Volt meters are virtually no load.. so you could be driving along during the day on your diesel tractor that basically uses virtually no electricity.. your almighty golden rule the world volt meter tells you no problem.. my needle is somewhere around 12.. so you are happy, sun is shining, life is good, and then you turnt he tractor off by pulling the kill cable, and find that the battery has 12v on it al right.. with no load.. but turing ont he headlamps makes it drop to 4v and it won't try to start.

Your amp meter ont he other hand would have been swung negative into the discharge area telling you.. hey dummy driving the tractor.. your battery is draining, do something, help, help.. then you might have actually gotten back home or to the trailer instead of needing a fresh battery out in the middle of your thousand acers.

remember.. volt meter said.. fine.. I see 12v under no load.. you are good. ammeter is telling you.. hey.. the volt meter is an itiot.. you are draining your battery.. do something.

It's straight electrical fact.... A volt meter on a unloaded week battery will lie to you every time.. the ammter will shouw you that charge rate.. and it don't matter if you can read the numbers on the gauge or not. if the needle is on the right side of the gauge, you are good, as long as it's not way right, and staying there for an extended time.. if it's on the left, you are bad.

But yeah.. you have to understand what your gauges are telling you.. your voltage gauge tells you one thing... voltage... and that's basically useless... it's nothing you can't figure out when you turn the key and hit the button. the amp gauge tells you stuff while you can still do something about it..

The sad part is.. most people aparently can't read gauges, including oil gauges.. and idiot lamps are well named.
 
Not really sure what your point is here.... Either gauge or an 'idiot' light will all tell you the same thing if you know how to pay attention to them. Personally I prefer the idiot lights because they remove the falacies of mechanical gauges from the scheme. A dim light at idle can indicate low oil pressure or high electrical load/low charge respectively... whereas a gauge with a vibrating needle bouncing around tells you absolutely nothing... with the added advantage that most of the time you can't see a 2" gauge in any meaningful increment anyway.

Rod
 
It would be difficult to give you a meaningful answer without knowing how the ammeter is wired. If it's wired correctly ie it's the link between the electrical system and battery... then a continuous 20 amp load is probably indicative of a very low battery or bad battery. However, if the ammeter is wired as a link between the alternator and the electrical system, all it's indicating is electrical output. That will then vary with electrical load... and that could very well be a normal figure.

Rod
 
Agreed on 2" vibrating gauges being iffy when you are rolling thru the pasture.

I'd take a charge indicator lamp or a center 0 ammeter over a voltmeter any day. At least a charge indicator lamp tells you you are discharging your storage battery.
 
Like this did?
Light caught my eye first.
WT?
Looked at Volt meter, WOW not good!
I bet IF there was just a AMP meter it would have read 0. No Problem right. WRONG!

Keith
a156618.jpg
 
What happened to cause this, one might ask.
A stick or branch came up and knocked the Neg terminal off the battery.

Just what happened.
Keith
BTW
I didn't "smoke" the Alt either.
Surprised me!
 
you apparently don't understand how an amp meter works... so your statement betting it would read 0 well.. would be incorrect.... thus your conclusion based on incorrect asumptions, would also be incorrect.

a center 0 net wired ammeter would show a negative deflection.
 
I agree with Rod - it would depend on how it's wired. If it's wired the way it's supposed to be, then it will show how much current is going into the battery ("charge") or out of the battery ("discharge"). Once the system voltage has stabilized at 14.6 volts, it should be showing near zero all of the time, unless the battery has a shorted cell ("charge") or the alternator is not keeping up with the loads ("discharge").

If it's wired in series with the alternator output, then your reading will be directly related to how much current your present loads are consuming, PLUS whatever is going into the battery to charge it. Once the system is at 14.6 volts, current going into the battery should be near zero, and loads should be also near zero as well if you have electronic ignition and no lights on. 20 amps continuous sounds like an issue somewhere to me.

Myself, I prefer a voltmeter. If your alternator stops charging, you'll never notice the discharge on the ammeter if you have next to nothing for loads on the system.
 
(quoted from post at 19:21:10 04/06/17) Except when it's not true....

With a modern hi power alternator, and a battery with a marginal cell , you can have normal system charge voltage.. say.. 14.4v.. but be pumping 10-20+ amps becuase of that marginal cell. it's not a short.. and the alt can keep up.. but it's sure not normal. That's one of those things a volt meter can't tell you, that an ammeter can.

You can have a marginal battery that has a bad cell, start up in the morning, have that alt cook that battery while you are mowing.. volts will be fine, and as long as the load isn't over the alts rated capacity, it will make em. you could be pumping 35-55 amps into a battery till it runs bone dry from boiling, then virtually becomes an 'OPEN'.. your voltage gage will still say 14.4v and your lamps and electrics will work.. but when you stop at lunch or to get fuel, you might not even get a click! An ammeter would have told you something was very wrong, while the volt meter just told you one thing... voltage.

the charge rate that amp meter displays is telling you multiple things about your charge system, you just have to be smart enough to understand it's language. Volt meter tells you a single thing... voltage.. and in the big scheme of things, voltage means less than amps. Want proof? go get 2 6v lantern batteries and wire them in series and check with a meter.. that will say a little over 12v.. just about the same as your car battery.

which one will start you car? that's right.. the one with the amps...

Most of this rambling on you talk is not true either. You are so consumed with a amp meter you fail to understand the value of a voltmeter, the first tool of choise when diagnosing a electrical circuit.
 
(quoted from post at 18:33:22 04/06/17)
(quoted from post at 19:21:10 04/06/17) Except when it's not true....

With a modern hi power alternator, and a battery with a marginal cell , you can have normal system charge voltage.. say.. 14.4v.. but be pumping 10-20+ amps becuase of that marginal cell. it's not a short.. and the alt can keep up.. but it's sure not normal. That's one of those things a volt meter can't tell you, that an ammeter can.

You can have a marginal battery that has a bad cell, start up in the morning, have that alt cook that battery while you are mowing.. volts will be fine, and as long as the load isn't over the alts rated capacity, it will make em. you could be pumping 35-55 amps into a battery till it runs bone dry from boiling, then virtually becomes an 'OPEN'.. your voltage gage will still say 14.4v and your lamps and electrics will work.. but when you stop at lunch or to get fuel, you might not even get a click! An ammeter would have told you something was very wrong, while the volt meter just told you one thing... voltage.

the charge rate that amp meter displays is telling you multiple things about your charge system, you just have to be smart enough to understand it's language. Volt meter tells you a single thing... voltage.. and in the big scheme of things, voltage means less than amps. Want proof? go get 2 6v lantern batteries and wire them in series and check with a meter.. that will say a little over 12v.. just about the same as your car battery.

which one will start you car? that's right.. the one with the amps...

Most of this rambling on you talk is not true either. You are so consumed with a amp meter you fail to understand the value of a voltmeter, the first tool of choise when diagnosing a electrical circuit.
h crap! now you dun it. went & woke Hobo up! :)
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top