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Amp gauge VS Volt meter...

B

banjoman09

Well-known Member
Changing my Oliver over from 6V to 12V...original guage is an Amp Meter; should I stay with that or replace with a volt meter? Thanks.
 
Either way, you know if you're charging the battery. If, for some odd reason, you have an extra hole in the dash, go for one of each!!
 
I prefer a volt meter for function and simplicity.

If you're doing a rewire, eliminating the amp meter simplifies the wiring, no need to feed the charging wiring to the dash area and back, just go directly to the battery cable.

Plus a volt meter gives a quick and accurate reading on what the alternator is actually charging. You learn what is normal and what is not.

Just be sure to use a tractor or marine rated meter, something that will endure the weather exposure.
 
A museum piece where people will growl at you if the paint is a slight color off? Amp gauge.
A machine that will do lots of work and is still earning its keep? Volt gauge.
 
I still like an ammeter for originality, looks, plus it can provide an indication of charging or discharging amps. No harm in having one in the dash. However, if you want to add a volt meter to provide even more indication of the battery and charging system condition, they are cheap and easy to wire, GO FOR IT.

John T
 
Does the face still look good? Apparently it's still functioning? If so, leave it there. What are you doing about a charging system? If an alternator, will its' capacity exceed the range on the gauge? That probably wouldn't hurt the gauge, but you might not like the way it looks.
 
Having both is preferable but I prefer having an ammeter if I had to pick one. If something is discharging your battery after you shut the tractor off an ammeter will show that, a voltmeter will not.
 
Contrary to popular belief,a idiot lite is the best. A idiot lite will get your attention the instant something is wrong. That's really all you need.
 
Im good at NOT giving all my information; Im changing my oliver 88 from 6V to 12V and it is a 12V generator; just wondered if using an "amp" guage would still be the thing to do...thanks for all the ideas:)
 
I suspect ammeters are gone now mainly because of safety and cost. Its not safe to have all the electrical power running through an ammeter and it costs more to do so. Running at least a 10ga or larger hot wire from the alternator, into the cab or dash and back to the battery or +bus can create hazards and also be problematic if connections get loose or wiring shorts to ground. Adding electrical loads and/or upgrading alternators can overload these circuits or the gauge too.

Volt gauges can be safe, they can be wired with small gauge wires with low amperage circuit protection. They will indicate if the charging system is working, They can also indicate the battery state of charge before engine is running and also indicate an over charge immediately. So, volt gauges are cheaper, safer and actually offer a little more information than an ammeter. If someone wants to know it all then use both.
 
(quoted from post at 22:45:59 06/07/20) I suspect ammeters are gone now mainly because of safety and cost. Its not safe to have all the electrical power running through an ammeter and it costs more to do so. Running at least a 10ga or larger hot wire from the alternator, into the cab or dash and back to the battery or +bus can create hazards and also be problematic if connections get loose or wiring shorts to ground. Adding electrical loads and/or upgrading alternators can overload these circuits or the gauge too.

Volt gauges can be safe, they can be wired with small gauge wires with low amperage circuit protection. They will indicate if the charging system is working, They can also indicate the battery state of charge before engine is running and also indicate an over charge immediately. So, volt gauges are cheaper, safer and actually offer a little more information than an ammeter. If someone wants to know it all then use both.
Click to expand...

" Its not safe to have all the electrical power running through an ammeter and it costs more to do so. Running at least a 10ga or larger hot wire from the alternator, into the cab or dash and back to the battery or +bus can create hazards and also be problematic if connections get loose or wiring shorts to ground."

For MANY years GM used a current shunt under the hood and light wires that were also fused to the Ammeter in the instrument panel.

Likely, some others did to.

Kinda debunks your theory of heavy wires to an Ammeter.
 
An amp meter will tell if you are charging or discharging. A volt meter will tell you the level of voltage or general level of battery. If system is good it should be something over 12 volts, like 13 or maybe 14 if charging and all is well. If less than 12 volts likely something is wrong, battery not good or not charging. Others with more electrical knowledge may improve on this but basically voltage level is condition of system, amp meter tells you charging or not. If battery is good and you you are charged up amp meter will not read much charge. If you just cranked a while to start it should show a good level of charge for a while to put battery back to full charge, then show much less but still not discharge while running. Turning on lights or ignition with engine not running will show some discharge, more for a bunch of lights than ignition.
 
(quoted from post at 07:25:15 06/08/20) The ammeters installed in the older tractors have an internal shunt. If you ad another shunt they will not read correctly.
Click to expand...

I did NOT suggest adding an additional shunt to an Ammeter NOT designed for use with an external shunt.

I was merely making the point that various OEM systems had an Ammeter WITHOUT the need to run the heavy, high-current wires all the way to the dashboard.
 
(quoted from post at 23:46:44 06/07/20)
" Its not safe to have all the electrical power running through an ammeter and it costs more to do so. Running at least a 10ga or larger hot wire from the alternator, into the cab or dash and back to the battery or +bus can create hazards and also be problematic if connections get loose or wiring shorts to ground."

For MANY years GM used a current shunt under the hood and light wires that were also fused to the Ammeter in the instrument panel.

Likely, some others did to.

Kinda debunks your theory of heavy wires to an Ammeter.
Click to expand...


If that were true wouldn't GM still have ammeters today, but they don't!!! Besides when did GM build tractors!!!!
 
(quoted from post at 20:10:37 06/08/20)
(quoted from post at 23:46:44 06/07/20)
" Its not safe to have all the electrical power running through an ammeter and it costs more to do so. Running at least a 10ga or larger hot wire from the alternator, into the cab or dash and back to the battery or +bus can create hazards and also be problematic if connections get loose or wiring shorts to ground."

For MANY years GM used a current shunt under the hood and light wires that were also fused to the Ammeter in the instrument panel.

Likely, some others did to.

Kinda debunks your theory of heavy wires to an Ammeter.
Click to expand...


If that were true wouldn't GM still have ammeters today, but they don't!!! Besides when did GM build tractors!!!!
Click to expand...

GM and other car manufacturers don't have ammeters today because of cost and the fact that the general public has no clue what the ammeter readings mean. That's the main reason why car manufacturers went to idiot lights instead of ammeters.

GM did build tractors:
https://en.m.wikipedia.org/wiki/Samson_Tractor

However, whether GM built tractors or not is irrelevant to the discussion. Ammeters work on the same principles whether they are installed in tractors or automobiles. Many ammeter manufacturers sold the exact same ammeters to both tractor and automobile manufacturers.
 

When doing diagnostic work the first info we gather is VOLTAGE WHODATHUNKIT... If we need to dig deep we check the amperage, the first info we need is the VOLTAGE.
 
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