Ammeter or voltmeter?

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63SplitWindow

63SplitWindow

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I'm in the process of rewiring my 73 Dart for track use only. The car has the original dash and working ammeter still installed and but I'm thinking a voltmeter may be more useful at the track. Thoughts?
Thanks,
Bill
 
They don't give you the same information - ammeter tells you something is wrong in the charging system, Voltmeter tells you the result after it's too late to fix it before you are stuck (glorified idiot light - yes I have opinions). I always have both because an undramatic over or undercharge issue might not be spotted on the ammeter over a long time, but will result in an under or over charged battery that shows up on the voltmeter. In a race car you can wire an aftermarket ammeter and voltmeter without the worries associated with worn out, unmaintained stock systems
They are cheap insurance...
 
Yeah, I know the difference. He has a system that WORKS and wants to change it.
 
Voltmeter is better, but for the small benefit, not worth changing if the ammeter is working.
 
str12-340 said:
They don't give you the same information - ammeter tells you something is wrong in the charging system, Voltmeter tells you the result after it's too late to fix it before you are stuck (glorified idiot light - yes I have opinions). I always have both because an undramatic over or undercharge issue might not be spotted on the ammeter over a long time, but will result in an under or over charged battery that shows up on the voltmeter. In a race car you can wire an aftermarket ammeter and voltmeter without the worries associated with worn out, unmaintained stock systems
They are cheap insurance...
Click to expand...
I guess I could keep the ammeter and just add a voltmeter so I could have both...
 
Pilots find ammeters useful. I do too. Running a fuel pump, radiator fan, trans cooler fan, lights etc. I like monitoring it, what the alternator and regulator are doing when using one electrical component or any combination. And the needle moves around, provides more visual action than a voltmeter! :eek:
 
What an ammeter cannot tell you is if the charging system is overcharging.
A voltmeter that moves to 16v would be an indication that the charging system voltage is too high & needs to be checked. Similarly, a reading of 11v indicates no/under charging.
 
Bewy said:
Voltmeter is better, but for the small benefit, not worth changing if the ammeter is working.
Click to expand...
Kinda what I was tryin to say. Thanks for summing it up better.
 
Ammeter shows if the Battery is overcharging.
Ammeter in cars and trucks are measuring current to or from the battery.
Voltmeter shows the voltage at the location its connected into the system.

If your race car is getting required for electric pumps, fans, or EFI, the ammeter wiring strategy needs to be changed or at least beefed up.
If the battery is moved to the trunk, the ammeter may be kept depending on how kill switch and starter are wired in.
for example questions about battery disconnect wiring
 
63SplitWindow said:
I'm in the process of rewiring my 73 Dart for track use only. The car has the original dash and working ammeter still installed and but I'm thinking a voltmeter may be more useful at the track. Thoughts?
Thanks,
Bill
Click to expand...
I use a digital voltmeter in the rear bumper of my dart and a Autometer voltmeter in the dash.
The digital helps with knowing the exact state of charge where those decimal points matter.
 
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