You asked a good and logical question at the beginning of this thread. Many folks who responded don't seem to understand what you were intending to do, and why.
I did, because I've had such a setup on my boat for many years (pics), i.e., a simple analog ammeter which directly measures alternator
output. It is via a shunt in the positive output cable.
The meter is named "Phoenix" (I tend to name many of my boat's equipment
I've found it to be extremely useful to give an indication of alternator
performance at various RPMs and stages of battery charging
. It also gives a good indication of how well the regulator
is functioning (in my case, the Balmar
Paired with a good digital voltmeter, I've found it's all I need....no need for an "amp counter".
It's mounted where it can be easily seen from anywhere in the cabin
, and the analog needle is all I need to see.....don't have to squint to try to read digital numerals in sunlight as I might have to with a digital ammeter. The digital voltmeter shown in the second picture is an illustration of this....you can't read it because of the glare.
Ditto for the two analog meters shown below in the second pic. These are AC volts and AC amps from the diesel generator