Alternator gauge question

Maybe something became mis--wired

IS the gauge centered with everything off?

Try "with engine off" turn on some loads, heater, radio, turn signals, anything you can. Does the meter deflect discharge for each, appropriately?

Do you have anything added, like electric fans, big stereo amp?

You say "everything is functioning fine." What does that mean? Have you checked charging voltage at the battery? What does it read?

Here's what I'm thinking?

If you changed some wiring, or added some loads, (like electric fans) and hooked them to a battery source under the hood, TWO things will happen

1 The new load, connected to the battery, will NOT show discharge through the ammeter with the engine off

2 This will ALSO skew the gauge reading. Let's say you had a big fan turn on, ON AN OTHERWISE normally operating system, with the ammeter CENTERED as per "normal."

IF the load is connected on the "wrong side" of the ammeter, and the fan turns on, it will now SHOW A CHARGE by the same amount of amps which the load draws.