6-4. 200 AMPERE ALTERNATOR (A0013036AA) TESTING AND REPAIR (Cont' )
Perform diode trio panel assembly tests as follows:
(a) Set ohmmeter to RX1 scale and connect POSITIVE probe to the field POSITIVE lead (#10) and
the NEGATIVE probe to the three long leads. A LOW resistance (zero or close to zero) indicates
a defective diode. Replace diode trio/brush holder assembly. If a HIGH resistance reading is
noted, then continue with step 17.(b).
Reverse ohmmeter probes and connect them to the same test points as in step 17.(a). A HIGH
resistance indicates a defective diode. Replace diode trio/brush holder assembly. A LOW
resistance reading for each of the three leads indicates that diode trio is acceptacle.
The diode trio is acceptacle when a HIGH resistance reading is
noted for each of the three leads in step 17.(a) and a LOW
resistance reading is noted in step 17.(b).
Connect ohmmeter test probes to diode trio panel lead #10 and #4. If ohmmeter needle deflects
and then climbs to HIGH resistance (100,000 ohms or higher), then capacitor is acceptacle. If
needle does not deflect, then reverse test probes.
If needle deflects and then climbs to HIGH resistance, capacitor is acceptable. If needle does
not deflect, or if it shows LOW resistance (less than 100,000 ohms), then capacitor is defective
and diode trio/brush holder must be replaced.