AMPS or Voltage?

[Godslayer]

This might seem like a dumb question but what the hell The ammeter in my 86 GT doesn't work. It sits right in the middle at all times. I plan on replacing it with an autometer eventually but have a few questions:

1) Does the guage measure AMPS or Voltage? (It's labeled AMP)

2) I assume I will be replacing it with a Voltage guage right?

Or should I replace it with an ammeter? Which is more important? I haven't measured the AMPS but the voltage is ~14.5v at idle. Thanks guys.

Please don't be infuriated by my lack of electrical knowledge.


Bob