Does this mean the ammeter is not hooked up at all?
The ammeter is an "inline" gauge, and an integral part of the main circuit. If just left disconnected, you won't have power to a great deal of the car.
If you don't feel comfortable with the condition of the ammeter and prefer to eliminate it (even if just temporarily), the two leads that connect to it need to be joined together once removed from the gauge. A small machine screw and nut are all that is needed to connect the two ring terminals, and wrap it well with electrical tape.