TM10-3930-660-34 6-3.  ALTERNATOR - REPAIR/TEST (Cont’d) e.  If both readings on same set of connectors are either high or low, the associated diode is faulty and entire diode trio must be replaced. 2.  TEST RECTIFIER BRIDGE (23). a.  Connect ohmmeter from grounded heat sink (48) to diode terminal (49) and note resistance reading. b.  Reverse ohmmeter leads or reverse meter polarity and again note resistance reading. c.  At one polarity, resistance reading should be low and at the other polarity, resistance reading should be very high, if diode is good.  If diode is faulty, both readings will be either low or high. d.  Repeat above sequence between grounded heat sink (48) and diode terminals (50 and 51), and then between insulated heat sink (52) and each diode terminal (49, 50 and 51). e.  If any set of readings indicates a faulty diode, replace complete rectifier bridge (23). 3.  TEST ROTOR (7) FOR SHORT OR OPEN CIRCUITS. a.  Connect ohmmeter between slip rings (53), in turn, and rotor shaft (54) (connection A).  Observe resistance reading on ohmmeter. b.  Resistance reading should be high (infinite).  If not, rotor (7) is defective and must be replaced. c.  Connect ohmmeter leads across slip rings (53) (connection B).  Observe resistance reading on ohmmeter. 6-6

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