Check for continuity in each direction, between the B terminal (A) and P terminals (B), and between the E terminal (C) and P terminals (B) of each diode pair. All diodes should have continuity in only one direction. Because the rectifier diodes are designed to allow current to pass in one direction, and the rectifier is made up of six diodes (six pairs), you must test each diode in both directions for continuity with an ohmmeter that has diode checking capability: a total of 24 checks.