TM 9-4910-663-34
Table 2-5. TROUBLESHOOTING (Continued)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
as in step 1. Set AC AMMETER OUTPUT CURRENT SELECT switch S25 to T3 position. Connect
test lead from positive DC VARIABLE VOLTS OUTPUT binding post to ALTERNATOR T3 binding
post, and connect another test lead from rectifier chamber T3 binding post to REGULATOR B+
binding post. Make certain that DC VARIABLE POWER SUPPLY 0-32 VDC control T5 is set fully
counterclockwise. Set circuit breaker switch CB1 to ON position. Set LOAD SELECTION 0-25
AMPS/ 0-12.5 AMPS switch S24 to ON position. Set MASTER LOAD DISCONNECT switch S8 to
ON position. Set DC VARIABLE VOLTS switch S10 to ON position, and adjust DC VARIABLE
POWER SUPPLY 0-32 VDC control T5 slowly to provide 20 volt indication on DC VOLTMETER
OUTPUT VOLTAGE meter M2. Adjust VARIABLE LOAD control R32 slowly to provide 14 ampere
indication on DC AMMETER LOAD & STARTER OUTPUT CURRENT BATTERY CHARGE
CURRENT meter M3. (It may be necessary to readjust DC VARIABLE POWER SUPPLY 0-32 VDC
control T5 to obtain 14 ampere indication.) Check to see that pointers of AC AMMETER OUTPUT
CURRENT meter M5 and DC AMMETER FIELD CURRENT meter M7 deflect slightly when
MASTER LOAD DISCONNECT switch S8 is set to OFF position, and when switch S8 is set back to
ON position. Repeat check with AC AMMETER OUTPUT CURRENT RANGE switch S26 set to X5
position.
If either meter shows slight deflection in only one position of AC AMMETER OUTPUT
CURRENT RANGE switch S26, replace switch S26. If neither meter shows slight deflection,
perform continuity check of circuit associated with transformer CT3 and AC AMMETER OUTPUT
CURRENT SELECT switch S25, using ohmmeter; replace defective parts.
16.
MILLIVOLT METER MILLIVOLT DROP METER CIRCUIT
a.
MILLIVOLT METER MILLIVOLT DROP METER CIRCUIT INOPERATIVE OR PROVIDES INCORRECT
INDICATIONS DURING TEST OF EXTERNAL COMPONENTS.
Step 1.
Set all controls to preliminary positions listed in table 2-2. Set FIELD CIRCUIT switch S32 to
MANUAL position. Connect ohmmeter between GENERATOR G+ and GENERATOR F binding
posts, and adjust FIELD CURRENT 0-30 AMPS (MAX) control R26 for 10-ohm indication on
ohmmeter. Disconnect ohmmeter. Connect test lead
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