Rectifier ASSEBMLY

Check the condition of the (+) heat sink by checking continuity between the (+) heat sink and each of the stator coil lead connecting terminals.
If continuity is present for both terminals, the diode is shorted. Replace the rectifier assembly.

Fig 1: Checking Continuity Between (+) Heat Sink And Each Of Stator Coil Lead Connecting Terminals
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Check the condition of the (-) heat sink by checking continuity between the (-) heat sink and each of the stator coil lead connecting terminals.
If continuity is present in both directions, the diode is shorted. Replace the rectifier assembly.

Fig 2: Checking Continuity Between (-) Heat Sink And Each Of Stator Coil Lead Connecting Terminals
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Check the condition of the diode trio by testing continuity of each of the three diodes using a circuit tester connected to both sides of the diode.
If the same reading results for both polarities, the diode is defective. Replace the rectifier assembly if any of the diodes is defective.

Fig 3: Checking Continuity Of Each Of Diodes Using Circuit Tester
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.