Ammeter question....

[ovrszd]

An ammeter will tell you if the battery is charging or discharging, but it will not tell you how charged the battery is, so if the battery has a bad cell and is at 11 volts after starting the tractor and continuously charges but never gets above 11.5 volts, everything will look good on the ammeter, but the battery may not start the tractor next time you go to use it.

Aaron Z

Bingo. Or Yahtzee. Depending on your preference.

That right there is my primary reason for preferring a volt meter. I am primarily told the condition of my battery. The fact that it also possibly reflects the condition of my charging system is bonus.

 

[Richard]

I would wire everything back stock the way it was. It's been that way nearly 50 years working fine. Back when that tractor was designed all you really cared about was engine running above idle ammeter shows charging. Running needle moving left discharge means a problem with alt/gen, regulator or wiring problems.

Heh...that's impossible.

Though the engine ran, not much else worked when I bought it (Tach worked and temp gauge)

Most of the wires behind the dash had rotted sheathing, many many of them were dangling, not attached to anything (they might have been snipped at one time but I don't know that)

I bought new Ammeter though I don't recall why... been too long.

So Ammeter, ignition, and the entire wiring harness have been yanked out and replaced with new.

TODAY, virtually everything works..... all exterior lights, dash lights, shift illuminator light....everything. I now don't think anything is wrong nor, miswired here. I think I was just working under the wrong pretense on how it should work.

I hope to later today, drag both batteries out there and hook things up to verify.

Even if it's wired wrong, about the only thing I was scratching my head on was the Ammeter.... machine runs fine so I'm going to have to prove to myself that something is wrong, otherwise it's going to stay as is. It's 1,000% better than it was prior to the rewire.

drove me nuts seeing all those dangling wires.... I didn't know if I was a bump and shifted wire away from smoking the harness by shorting a hot wire. In the end, I don't think I was as my fuse was also destroyed (and got replaced with new). One nice thing about putting the new harness on.... though the instructions could have been a bit more clear, I had the existing wires in place to give me some ideas of how to snake them through places. Just took it one section at a time..... started at the alternator & did the front of the machine.... then the dash section, then the fender lights. Since the 1066 evidently came stock with a SINGLE light in each fender, and this tractor has dual lights, I had to do a bit of splicing to bring both into the circuit.

 

[Richard]

An ammeter will tell you if the battery is charging or discharging, but it will not tell you how charged the battery is, so if the battery has a bad cell and is at 11 volts after starting the tractor and continuously charges but never gets above 11.5 volts, everything will look good on the ammeter, but the battery may not start the tractor next time you go to use it.

My expectation on how this would work WAS:

Start machine, that costs you some battery power. So, as machine is running, the ammeter SHOULD show NEGATIVE and as the battery returned to a full charge, the needle would tend towards zero.

What I EXPERIENCED: Start machine, needle jumps to (let's say) +1.... turn lights on (bigger drag on system) and the needle goes to (let's say) +3 HOWEVER, the more it runs, the more I expect it to DWINDLE DOWN to zero indicating that the system isn't now charging the battery as much.

So though I think I "got it", I got it from the wrong perspective. I think I was describing more the workings of volt meter rather than ammeter. Reasonable???

 

[WranglerX]

Let me change the subject slightly......

I have an ammeter. What if instead, it was a volt meter.

As a practical matter, what's the benefit of one over the other? (if any)

IF voltage is above resting voltage of battery then system is (alternator/generator) is supplying sufficient amperage to charge battery and supply electrical needs. ITs in a charging state

IF voltage is below resting voltage of battery then system IS NOT getting enough current from Alternator/generator to charge battery and supply system needs... Its in a discharge state

Lets say if battery is in resting state reading is 12.88 volts (just measuring battery voltage with everything off) .

Now start engine....

IF voltmeter is reading something like 13.85 or more volts, then system is charging.

IF voltmeter is reading 11.95 volts (or anything less then the above example of 12.88 volts) the system is in discharge state.

Keep in mind actual battery voltage is a result of chemical reaction inside battery ... We say a typical automotive battery is 12 volts but actually it some want more (something a bit over 13.2 volts...

Also helps to know some about batteries...

Car and Deep Cycle Battery FAQ, Battery Manufacturers and Brand Names List, and

Dale

 

[ruffdog]

A volt meter is simpler and cheaper to install. With the voltmeter, you can locate it anywhere and all you have to do is run a small wire for sensing the voltage to any convenient spot. With an ammeter, you have to install heavier wires from the point you want to measure to the meter. The longer the run, potentially you can have a larger voltage drop to the system. Also, when you get into 100+ amp systems, like a lot of automotive systems today, that can be problematic. A solution to this would be the use of a shunt type ammeter, but it also has its weak points. For those that have been around ammeters for a long, long time, when you start to see a steady increase in charging current for no apparent reason, you will recognize that there is a problem developing with the battery.

That is why in high amp systems, a voltmeter is easier and cheaper.

Yes, once you are use to looking at ammeters, it is easy to see something is wrong.

 

[WranglerX]

Interesting stuff!

I can see where the volt meter would be of benefit..... actually, I think I was looking at the operation of the ammeter from the viewpoint of how the voltmeter would work as I've been looking at it as an indication of my batteries health/charge. Looks like instead, I was monitoring the charging systems health!!

Do they make a dual purpose gauge (same size) that does both?

Yes, but it has to be wired correctly to be of any use...

Be careful because most digital voltmeter with ammeter have very small/limit range for measuring amperage....

https://www.amazon.com/Voltmeter-AiTrip-Accuracy-Automotive-100V-10A/dp/B07KFVD11B


https://www.amazon.com/Spartan-Powe...PK82F21YCHZ&psc=1&refRID=J4PPN180DPK82F21YCHZ


Dale

 

[aczlan]

My expectation on how this would work WAS:

Start machine, that costs you some battery power. So, as machine is running, the ammeter SHOULD show NEGATIVE and as the battery returned to a full charge, the needle would tend towards zero.

Nope, ALL the ammeter tells you is which direction power is going through it and how many amps are going through.
So, machine off, if you put a meter on the battery it would read 12.5V.
You start the machine (that does not go through the ammeter), alternator wakes up and starts charging the battery. The ammeter reads let's say +25A because the alternator is adding 25 amps to the battery, the volt meter reads 14.8V.
Turn the lights on and the voltage momentarily dips to 14V, then comes back to 14.8V, when the voltage dips the ammeter will also swing back towards 0A, then go back to +25A until the battery finishes charging, at that point the voltmeter still reads 14.8V and the ammeter will read 0A.

What I EXPERIENCED: Start machine, needle jumps to (let's say) +1.... turn lights on (bigger drag on system) and the needle goes to (let's say) +3 HOWEVER, the more it runs, the more I expect it to DWINDLE DOWN to zero indicating that the system isn't now charging the battery as much.

So though I think I "got it", I got it from the wrong perspective. I think I was describing more the workings of volt meter rather than ammeter. Reasonable???

Turning the lights on (assuming that the lights are on the alternator side of the ammeter) should not change the ammeter reading UNLESS the alternator is maxed out and can't keep up with charging the battery and supplying power to the load (from the lights, etc).

Aaron Z

 

[Richard]

Just got back from starting the tractor.

Side note.... as I understand, the stock alternator (in amp size) was no longer available.... so instead of having (let's say) a 90 amp (50?) alternator, I have a 110 amp alternator. Whatever the original size in output was, this new one is slightly more. AND all the lights except for the dash lights were replaced with LED's so the way I see it, I have more juice available from the alternator however, I have collectively, smaller demand.

(don't know if that matters to know or not)


Anyway, just went out, put both batteries in (two 12V long skinny type verses two 6v).

The lights, all of them, work totally as expected EVEN WITH THE KEY OFF. Turn light switch, and they come on.

During this non-running time, I was staring at the (again, brand new) ammeter and though the engine was OFF, it didn't budge at all. Didn't slide upwards, nor did it slide downwards. It was as though it was simply dead.

(side question..... all lights are now LED's, would they draw enough power like that to make it show??) I would deduce they must show since they show the change from "+1 to +3". Interesting.


Started the engine and AT IDLE, the ammeter just sat there, pegged at zero. Once I revved the engine a bit, THEN it perked up and went to (let's say) +1. When I turned the lights on, then it went to (let's say) +3.

Turning key off/back on had no effect on the meter, even while engine running.

However, after reading all this info (which is fantastic by the way), I'm now curious if maybe I don't in fact, have a wire hooked to point "B" instead of point "A"....

I don't think I've EVER witnessed the meter showing anything less than zero and typically, it's at the +1 mark because I don't do anything yet requiring any lights.

 

[aczlan]

Just got back from starting the tractor.

Side note.... as I understand, the stock alternator (in amp size) was no longer available.... so instead of having (let's say) a 90 amp (50?) alternator, I have a 110 amp alternator. Whatever the original size in output was, this new one is slightly more. AND all the lights except for the dash lights were replaced with LED's so the way I see it, I have more juice available from the alternator however, I have collectively, smaller demand.

(don't know if that matters to know or not)


Anyway, just went out, put both batteries in (two 12V long skinny type verses two 6v).

The lights, all of them, work totally as expected EVEN WITH THE KEY OFF. Turn light switch, and they come on.

During this non-running time, I was staring at the (again, brand new) ammeter and though the engine was OFF, it didn't budge at all. Didn't slide upwards, nor did it slide downwards. It was as though it was simply dead.

(side question..... all lights are now LED's, would they draw enough power like that to make it show??) I would deduce they must show since they show the change from "+1 to +3". Interesting.


Started the engine and AT IDLE, the ammeter just sat there, pegged at zero. Once I revved the engine a bit, THEN it perked up and went to (let's say) +1. When I turned the lights on, then it went to (let's say) +3.

Turning key off/back on had no effect on the meter, even while engine running.

However, after reading all this info (which is fantastic by the way), I'm now curious if maybe I don't in fact, have a wire hooked to point "B" instead of point "A"....

I don't think I've EVER witnessed the meter showing anything less than zero and typically, it's at the +1 mark because I don't do anything yet requiring any lights.

From those symptoms I would say that your lights, ignition switch, etc are definitely on the battery side of the ammeter vs the alternator side where it should be.

Aaron Z

 

[WranglerX]

This is "concept" on how a voltmeter and/or ammeter should be wired....

Does not matter if car or truck or tractor or bus or gas engine or diesel... Electrical are electricals...

Dale