Generator Design: Rectifier
WARNING: This page is about a different car, the 2003 Saab 9-3. However, it is still accessible from the selected car via links, so may be relevant.
Courtesy of SAAB-SCANIA OF AMERICA, INC.
The voltage generated in the stator winding must be converted to direct current before it can be used in the car's electrical system. This is done by six Zener diodes, two for each phase winding.