Alternator is working. I opened it. Checked the diodes, rotor, stator and brushes. All OK.
And I found another regulator for emergency case on Tereza (again previous owner had lot of experience- another case of when something broke and Tereza had the spare part, like it was the starter, then the raw pump repairing kit ). I have connected it and … immediately RPM of engine did decrees. That is the sign that alternator produces load while charging.
Again . I am learning.