Ammeter on discharge

The amp gauge needle should rest in the center even when the gauge alone is on a workbench. Its makeup is a magnet in between to little limbs. I've seen a few that had a pretty good accumulation of metal dust collected on the magnet. I can only guess it comes from the mechanical speedometer in the same housing. That debris would draw the needle slightly to one side. Anyway... There could have been arcing/welding inside it. Current still passes through the shunt.