Ammeter to Voltmeter...who does it?

Logan said

If I were to convert to a voltmeter, I'd grab a few voltmeters from fords or chevies next time I was at the junk yard, break them open, isolate the resistors and measure their values with a digital ohmeter. Then, break into the Mopar ammeter, remove the parallel shunt resistor and add the junk yard resistor- or radio shack equivalent- in series and maybe even outside the meter case if it was easier. Change the 'A' to a 'V' and go cruzin.

Click to expand...

Sorry, disagree. A series resistor --known as a multiplier--depends on the individual movement, I.E. a movement for a Ford MAY (or may not be) vastly different for a Chivvy.

Not only that but you can NOT remove the shunt from a Mopar ammeter of the type the car in this discussion originally used--because it is simply a huge piece of brass that causes needle deflection directly. That is, the "old school" Mopar "full current" ammeter HAVE NO meter movement "as such."

Only ammeters used in some of the later model cars (Mopars) that were external shunt are candidates for conversion such as you describe, and an experimental approach is probably more effective than messing with dissecting GM/ Ford units.

Here's a picture of a Mopar unit--just a brass shunt and a "moving vane" attached to the needle: