Well yes, but no.
Yes, amps is amps, and volts is volts, but gauges don't measure volts, they
measure current, typically in units of amps or fractions or an amp
(milliamps). A volt meter is simply an amp (current) meter reading across a
fixed load, and calibrated to show the result in volts.
You aren't going to read both off the same gauge unless the gauge has
multiple scales, and can switch the load on and off. Actually, such a
device is called a multimeter, and you can pick one up at your local Radio
Shack. The cheapest analog meters with no electronics are very similar in
principal to the amp meter or voltage meter you might find used in an
automotive application. The fancy digital ones are far more complicated,
but still are applying the same basic physics.
If you can determine the deflection properties of your amp meter, you should
be able to determine what load needs to be used to recalibrate it as a volt
meter. Of course part of the calibration required would be a face marked
with your voltage scale, but it could still be the same meter.
All a conventional electric gauge is is a ferrous metal needle mounted in a
pivot, and a coil of wire that becomes magnetic when a current passes
through it. There is no magical difference between an amp meter and a volt
meter, they both apply Ohms law to represent what's going on.
Its neither hidden nor trivial in its execution, but it could be done. My
biggest concern is that your amp gauge is calibrated to rest with the needle
in the center of the gauge (0 amps). I don't know if it can be adjusted to
rest on the extreme left, which is what would make most sense for a volt
meter. I've thought about doing this for my own, but some of the faces on
my gauges have deteriated to the point where I'm considering replacing the
whole set with after market stuff instead.
And yes, if your alternator puts out more than 35 or maybe 45 amps I
wouldn't be surprised if you smoked the meter, and perhaps some wiring along
the way. The gauge wasn't designed to carry the load of a modern
alternator. I'm still running a generator on my suburban, but with things
like power seats and electric wipers I'm thinking its soon going to be time
to convert, and at that time I may address the gauge issue personally
instead of in the abstract.
----- Original Message -----
From: "G. L. Perry" <glperry@fwi.com>
To: "Paul Moon" <capt2th@tehama.net>; "Oletrucks" <oletrucks@autox.team.net>
Sent: Thursday, April 10, 2003 12:34 PM
Subject: Re: [oletrucks] amps to volts
Amps is Amps, Volts are Volts. Cant read both off same gauge. The Amp gauge
in my 54 still reads amps off an alternator. I connected the two 10gauge
wires that used to be on the volt regulator to do that. What's wrong with
that? A volt meter can be connected to almost any hot source with key on and
reads. You would need a seperate meter for that. I suppose you could
tear-down your gauge set and a volt-meter body could be made to fit in same
place as Ammeter was. The face would need changing too, don't know what you
would do for that. The Speedometer Shop in CA (on-line) may be able to do
that. With Ammeter, if it swings to plus side should be charging OK, if to
minus side a problem. What's wrong with that?
G. L. Perry
Huntington, IN 46750
glperry@fwi.com
Big AD trucks, COE
MM tractors and 1 Oliver!
----- Original Message -----
From: "Paul Moon" <capt2th@tehama.net>
To: "Oletrucks" <oletrucks@autox.team.net>
Sent: Thursday, April 10, 2003 9:24 AM
Subject: [oletrucks] amps to volts
> Placed an alternator in the truck, but my dash guages (which I want to
look
> original) read the amps instead of volts. Is there a hidden way to alter
the
> incoming to have the ampmeter read volts. Heard there was. Anyone have
any
> info?
>
> Thanks,
> Paul Moon of Red Bluff, CA with the 55 2nd series almost done
> oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
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