Is there a way to bench test functionality of any Chrysler Ammeter gauge?

[WH23G3G]

I've got a couple spare gauge clusters and want to test the gauges. I'm not sure how or if you can even bench test the ammeter gauge. Is the needle suppose to be in the middle when it's just stationary - not hooked up or is it suppose to be at D? What do I need to test it safely?

[Ghoste]

It should be in the center position with no load on it.  Some may not be perfectly made and rest slightly to one side or the other without current passing through but it is supposed to be in the middle.

[Plumcrazy]

The needle should be in the middle if no current is flowing through it.

To test it, make a simple circuit with a horn or similiar high current device. Wire the ammeter in that circuit.
When the current flows in one direction the needle should move, reverse the current flow and the needle should reverse directions