Alternator polarity?

this might not be exactly your car (wire colors might be different) but what you basically have

upload_2020-6-27_18-25-52.png

The Alternator you should have (square back, 2 field wire)
upload_2020-6-27_18-42-15.png

The Alternator you probably have (square back, single field wire)
upload_2020-6-27_18-52-7.png



What you don't have (round back, single field wire)
upload_2020-6-27_18-47-6.png

I forgot to mention that the 0.5 ohm number is just my best guess of the resistance the field coil would have, but you get the idea