Alternator gauge is smoking
Remove the cluster. Remove the wires from the ammeter. Get a small wire brush and clean around the terminals of the ammeter very good. Also clean the attaching nuts and the eyelets on the end of the wires that attach to the ammeter. All of that needs to be CLEAN as possible. Sometimes, dust, dirt and even corrosion from the terminals being loose will make a poor connection and add resistance which will add heat, especially when the alternator is charging. Clean, clean, CLEAN! And TIGHT! But do not over torque.