Converting to 12V, Amp or Volt Gauge
 

My '51 Tudor is going to 12 volts with alternator. I intended to continue with the in dash original amp gauge. I am already going to have an under dash panel with two temp and one oil pressure gauge. Is there perhaps a reason (other than just having another gauge) to also have a volt meter gauge as well?

Re: Converting to 12V, Amp or Volt Gauge
 

Amps worked for years though volts would give you info on the condition of the battery but to me it wouldn’t worth the cost and installation labor to have both.

Re: Converting to 12V, Amp or Volt Gauge
 

Well that is what I'm kinda thinking. With the work of going from 6 cyl and 3 speed to a warmed flathead V8, 3 speed with overdrive, all new wiring, exhaust, and suspension stuff,...... if I don't need to add to the list I won't.

Re: Converting to 12V, Amp or Volt Gauge
 

Re: Converting to 12V, Amp or Volt Gauge
 

I just use a cell phone charge adapter that plugs into the cigar lighter. It shows the battery charge as you are driving. This gives you a quick view of the charge rate which should even out at higher speeds if the regulator is working properly. I have only seen these units for 12v vehicles. terry

Re: Converting to 12V, Amp or Volt Gauge
 

To me, an amp gauge is recipe for disaster. I prefer a volt gauge

Re: Converting to 12V, Amp or Volt Gauge
 

"To me, an amp gauge is recipe for disaster. I prefer a volt gauge"

Why is it a recipe for disaster? Please explain....

I've run an alternator and stock ammeter for years and never experienced a disaster [at least not electrically!]

Re: Converting to 12V, Amp or Volt Gauge
 

Yes, please explain your reasoning for this statement...

Re: Converting to 12V, Amp or Volt Gauge
 

If you suddenly run 100 amps through a 'hard-wired' amp gauge rated at say 60 amps, you may end-up with a VERY HOT (FIRE) amp gauge. Plus, volt meters can afford all sorts of usable information, vs an amp gauge. A volt meter can tell you that you lost a belt, among others.

Coop

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Re: Converting to 12V, Amp or Volt Gauge
 

An ammeter will also tell you if you lost a belt.
Bill

Re: Converting to 12V, Amp or Volt Gauge
 

I would think the temp gauge would do the same thing.

Re: Converting to 12V, Amp or Volt Gauge
 

My preference would be one temp gauge and a voltmeter in your under dash added panel. That way, you've got both amps and volts covered.

I've had temp gauges measuring each side of the engine, but save for the fact that I had room for two, the information wasn't that enlightening!!:rolleyes:

Re: Converting to 12V, Amp or Volt Gauge
 

"If you suddenly run 100 amps through a 'hard-wired' amp gauge rated at say 60 amps, you may end-up with a VERY HOT (FIRE) amp gauge."
What do you mean by hard wired? Do you mean an ammeter with two connections? The ammeter in my 35 works through inductance, ie, the wire passes through a loop at back of gauge. Reads + or - 30 amps. So, if I suddenly put 100 amps through it [doubtful, as my alternator doesn't put that much out, but if I fed 100 amps through that meter, it would/could catch fire? Really?
Coop, I'm not trying to be a wise guy, please elaborate....

Re: Converting to 12V, Amp or Volt Gauge
 

Even if it is the induction type you are still sending all the vehicle power through 1 long wire both directions. JMO

Re: Converting to 12V, Amp or Volt Gauge
 

Shoebox, I have the amp gauge wire reversed on my 49 with alternator, 12V, no issues for over 10 years. Run the stock gauges. Stock starter.

This is what I've used and have zero problems.

https://www.jalopyjournal.com/forum/...rnator.534156/

https://www.ronfrancis.com/category/...rsion-products

Also use a AGM battery.

Re: Converting to 12V, Amp or Volt Gauge
 

Here's an excellent article on AMP and VOLT gauges and "what they tell you".

https://fifthaveinternetgarage.blogs...-facts-vs.html

Here's more good reading about this topic.
https://www.google.com/search?q=why+...hrome&ie=UTF-8

Re: Converting to 12V, Amp or Volt Gauge
 

Guys,
Thanks for all the input! At this point the "Jury is still out" on this issue. Will be using the in dash Amp gauge. Might do as one suggested and have one temp gauge, oil pressure, and voltmeter in my under dash panel.

Re: Converting to 12V, Amp or Volt Gauge
 

Thanks 19Fordy, after reading that I feel much better!

Re: Converting to 12V, Amp or Volt Gauge
 

V8COOPMAN expressed my views on ammeters. Using a sock ammeter on a stock 6 volt system is usually no problem but when gong to 12 volts and the possibility of using additional electrical devices is, in my opinion, a invitation to disaster. Your opinion may differ.

Even with stock electricals (including a 6 volt system) if the ammeter goes bad it still can result in a fire. I have heard of this numerous times. Very rare with a voltmeter. Just think - you are running the total electrical load through a ammeter.


If you want to run what looks like a stock ammeter but is actually a volt meter, there are outfits that can do this. I think Williamson's in Arkansas is one.

Re: Converting to 12V, Amp or Volt Gauge
 

For the amp gauge, you are running heavier wire to it and through it... big enough wire to run the car, including headlights and whatever else you have that draws a bunch of current. And, this heavier wire has to be run from the engine compartment, through the firewall, and included with the under-dash wiring. In my opinion, safe enough with stock, properly installed and maintained wiring. But, also my opinion, if you have an aftermarket amp gauge, with homemade wiring, and if you screw up the install, there is the possibility of bad things happening.
On the other hand, if you go with a volt gauge, the wire to it can be very small (and fused small, if you like), and this wire will run the volt meter. If you screw up, and bad things try to happen, this small wire, or a fuse, can burn out, and no harm is done. So, for many (most?) modern cars, I think a 12V system, with a simple volt meter, is potentially a little more fool-proof and safer.