Alternator not charging

pulled dash to look at ammeter wires, all looks good with no corrosion or burn marks, so I guess I can leave that alone as long as I don't go higher the 50 amps of an ALT, is that right?

BTW I grounded the GRN terminal and the readings were the exact same as before.

Did Test by probing BATT NEG and then POS on ALT case and it read 0.1 to 0.2 max.

Did test by probing POS BATT and then while probing large BATT terminal at ALT and read 1.0 to 2.0 volts, what does that mean?