Ammeter to voltage meter.

I have been reading that having a volt meter is safer than running an ammeter. Is there a way to convert my current ammeter gauge to a volt meter? I want to keep the stick clucster in my 54 Chevy.

 

I"d like to know also,as I"v heard the opposite.

 

Not that I know of, they are two distinctly different instruments. Maybe you can slip out the portion of the cluster that is the ammeter and modify a voltmeter to slip into the same area and show through that way.

And you are right, a voltmeter is a much better, safer gauge to have.

Don

 

Its not hard at all. The ammeter is wired in series and a voltmeter is wired in paralell. Basically you can take the two wires to the ammeter and hook them together real nice. I like to solder them and use heat shrink. Then for the voltmeter all you have to do is find a hot with the key on and hook the voltmeter pos lead to it and ground the other lead. I would look for a 12 volt key on hot near the ign switch or even near the voltage regulator if its easy enough. Ron

 

False...... This is not a simple case of series and parallel.

Sounds like you are talking about replacing vs converting a gauge?

 

I believe the original question was "Can I convert my ammeter to a voltmeter"?
DO NOT try to connect your present ammeter like you would connect a voltmeter. Smoking wires would be the result. An ammeter has a shunt built into it to pass the majority of the heavy current required by the car's electrical system, and only a miniscule amount of current actually makes the ammeter needle move. A good instrument shop might be able to convert your ammeter to act as a voltmeter, but it isn't a project for the typical do-it-yourselfer.

 

ammeters are extremely dangerous, that is why there are no cars left older than about 1955. they all had ammeters and burned to the ground many years ago.

 

You've been reading the internet again.

 

Do as post #4 said,...Easy to do, and up to date. Many of the factory ammeters used an induction pickup, the wire ran thru a loop on the meter, with no physical connections to the meter. The "bad" installations ran everything thru the meter, and problems happened when the meter was no suited for the loads, and / or the wiring was the wrong size. This can happen with aftermarket meters, improperly added to cars originally equipped with an "idiot light". That said, the voltmeter is safest, and installs with no mods to the vehicle wiring.

4TTRUK

 

With all due respect, that's one of the most idiotic statements I've read on theis board.

 

I dont know what you are talking about but its not false. An ammeter has to be hooked in series to work as it reads current flow through the gauge and a voltmeter gets hooked in parellel as it hooks across a circuit to read pressure (volts). Anybody who knows about electrical should know that. I am not talking about converting the ammeter as I figured the poster would just get an aftermarket volt gauge and hook it up on the lower dash. He can leave the factory ammeter in the dash as to keep it looking stock. It just wont work. If he is talking about putting a voltmeter in the dash in place of the Ammeter then you have to get a volt gauge to fit in the dash. Its still simple to hook up. Ron

 

49ratfink has a warped sense of humor........ LMAO !

4TTRUK

 

Mopar use ammmeters up into the 70's. They did switch to a shunt type ammeter in the early 70's so the gauge would not move so much at idle. Thats what many cust complained about was the gauge moving to discharge at idle with many things turned on. I still use the factory ammmeter in my 63. It works fine and if it ever gives me trouble I will just rewire it. Ron

 

they do make high current breakers for 12 volt use, run one right after the battery and the entire system will be protected from a dead short

 

I wanted to keep the ammeter look on my 57 chev truck cluster, Don't have any pictures but what i did was remove the amp gauge, snipped off the original needle.Then a found a cheap rac voltmeter stripped it down to salvage the meter movement, Drilled out the face of the amp gauge and J=B weld the movement to the original face. I used super glue to attach the needle from the old gauge to the new movement.Works great and nobody really notices the needle is not in the middle of the gauge while it is off.

 

#4, #9, #16.

It's sad to know there are no more cars older than 1955.

 

I'm pretty sure there are at least a few cars built before 1955 that managed to survive having amp meters. True volt meters are less likely to cause trouble because primary voltage does not run "through" the gauge but that's what fuses are for.

Oh, and never let your high school class ring form a circuit between the plunger bottom solenoid and the hot wire lug on a '39 Ford flathead. It'll melt the sucker right on your finger. Lesson learned.

 

Uh...I'm pretty sure 49ratfink was being sarcastic. I think his statement is hilarious!

 

POST 1 OP specified "convert"

I said (the diff between voltmeter/ammeter) is not as SIMPLE as parallel vs series, which it isn't. If u think it is remind me not to ask you to wire anything in my car or on my bikes.

 

I recently upgraded the stock brake system to a dual circuit system, not cause the old ones didnt work, but because it was safer. That is my thought on the gauge swap. If it is some thing that can be done to give me piece of mind, why not try. Im not afraid of the ammeter causing problems, but would like to play on the safe side.

 

Huh, my 50 Olds 98, 53 Merc Monterey, and my 54 Lincoln Capri all ammeters, and guess what, they are all alive and well.

Sure they are dangerous if used with high current devices and alternators with high outputs, but with the old generators and low current devices, they are pretty safe.

I would use an ammeter with a shunt with good 10 gauge wire for a car that has a modern day alternator. But it would also be rated for +/- 100 amps too.

Voltmeters are definitely safer, but the one I have in my 03 Ranger is useless, since all it has is an L and H on it. Get yourself a good gauge with numbers on it.

 

Lighten up bud. No need to get your feathers in an uproar. You said it was false so I was replying to that. No need to get upset. And dont worry as I dont need to wire any more cars since mine are done just fine. Actually it is as simple as series vs parellel when it comes to wireing the gauges. But you have to take into consideration if you use a shunt type ammeter.
I see you live in Md so heck I might even know you ? Ron

 

Lot's of info here, some of which is pretty correct. I'm going to disregard the cars before 1955 comment. Also, the issue about ammeter versus voltmeter as a gauge - they are obviously different, and it would make no sense trying to convert one when both are readily available. The exception would be if you need the original look, and one of the clever posts had a solution for that. You'd just have to be creative and substitute a voltmeter gauge into the ammeter location and hook it up as a voltmeter

A voltmeter hookup versus an ammeter hookup, and the operation of the gauges, is as simple as series versus parallel. An ammeter is in series, a voltmeter is wired in parallel to the source. There were actually two separate factory methods of wiring an ammeter. One ran the entire system current through the gauge (early cars, but up to at least 1962 for Chevy). The other, in an effort to keep the heavy wire and current from under the dash, was a shunt hookup where a small sample of the current was measured to give you a gauge reading allowing much smaller (and less risk) wire under the dash. A voltmeter is hooked up in parallel across the load of the car and does not carry the current used by the engine and accessories. It's merely a voltage measurement as if you put a hand-held voltmeter across the two battery terminals.

There is a problem though regarding the safety issue. Just changing, or adding a voltmeter, doesn't do much to avoid risk unless you take some other steps. This applies mainly to the cars that have all of the current under the dash. Removing the ammeter and just connecting the wires together has removed the gauge but not all of the current running under the dash. If accessories or a larger capacity alternator or generator are added, and the same circuit connections are kept, a potentially larger current than before is now under the dash. The main problem could really be wire size. Wire of a certain size is only capable of handling a certain amount of current. If this is exceeded - smoke and burning. The absolute best way is to remove the current carrying wires to a location under the hood, and to change them to a larger size if the load on those wires has increased.

 

Ammeter vs. Voltmeter always seems to promote discussion. Each to is own. I personally prefer an ammeter because I can tell immediately if I have charge or discharge. Also I can see if I am overcharging over a period of time. I have never had an electrical problem with with ammeters (just take care to install properly).

 

I kept the OEM instrument cluster in my 46 Olds and upgraded all the movements, amp to volts etc etc. It still retains OEM look with modern electrics. I had a decal made for new perspex facia.

 

The were used on tractors, etc., well into the '70's. Not exactly the same thing, but still.

 

sar·casm
ˈsärˌkazəm/
noun

1. the use of irony to mock or convey contempt.

 

The old Fords were probably the safest, they used an inductive meter, no loose connections could occur, but rubbing though the insulation of the wire could cause issues.

But (I know it's an old subject) I do recall some internet articles about converting ammeters to volt meters, as I recall, volt meters were installed in place of the ammeter, and some creative lettering done.

And thinking about it...didn't some of the '40's Ford have a volt meter instead of an ammeter?...Thinking of cars, not trucks.

 

Yep along with single brake master cylinders and no disc brakes. I kinda remember dying bank in 1962 in a 55 Old sedan but not sure.....

 

Rocketman's Classic Cougar Innovations does conversions of Amp meter to Volt meter for a whole lot of Ford models (https://www.rccinnovations.com/index.php?show=menu-volt-all).

Question: I understand why the inline wired Amp meter is dangerous (connect a more powerful alternator to that thing and you risk having it go up in smoke). However is it also dangerous to use a loop style Amp meter with a more powerful alternator (or is the risk there only that the wire may rub a bare/open spot)?

I can't decide how to think about the physics on this. On the one had it is hard to believe that there would be meaningful heat coming from the gauge when it isn't actually physically connected to the wires... on the other hand I guess there could be enough induction energy transferring to cause that gauge to start smoking?

I guess an important additional question I should ask: If indeed it is safe to use a loop style Amp meter how will it behave if you use it on a system with a much more powerful Altimeter?

Thanks!
kevin