Chonic Alternator Failure
I disagree. All an ammeter can tell you is if charging or discharging and generally by how much. A voltmeter will tell all of that and the condition of the battery as well..
A voltmeter tells you nothing of the condition of the battery, unless it's measured with system OFF and in between engine runs long enough to dissipate surface charge. Most factory or even stuff like Autometer is not nearly accurate enough for really definitive readings.
An (good) ammeter is an EXTREMELY useful tool. An ammeter that does not run "centered" when under light load and cruising tells you a BUNCH
If it's not centered, it might be that due to system problems, the charging voltage is too high, IE "it always wants to charge."
The same indication can suggest the battery has a problem, IE sulphated
While a voltmeter OVER TIME will drop some under load, this is not always immediately apparrent. But an alternator that cannot keep up will IMMEDIATELY indicate a "left of center" view on the ammeter.
I grew up with ammeters. I still to this day would prefer a "good" one.
Unfortunately, they don't exist. When "everybody" went to remote shuts, which in real actual terms means "we all got C.S. and used the wiring harness for a shunt", many of these became so "numb" as to be completely useless. The 86 Ranger I just sold was so "numb" that if you switched on the headlights, engine off, you STILL had to stare intently at the needle to figure out if "it really moved."
