This is an old 914 non working alternator. Clay said I could change out the diode from a good working spare alternator. So I tore into this non working one to edumacate myself.

What part plays the diode(s)? 1. or 2. or neither?

This may help: https://www.thesamba.com/vw/forum/viewtopic...70a2e3d2c61ece7

Ron

Number 2 is the diode, #1 is the connection to the alternator brushes which provide the AC voltage/current. The diodes on the curved plate rectify the AC to DC 12 volts. That curved plate is 'hot' (12v) so it must be insulated from the alternator body.

Thanks Ron. That explained a lot.