TM 9-4910-663-34
Table 2-5. TROUBLESHOOTING (Continued)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
CURRENT RANGE switch S14 to X1 position. Set DC AMMETER FIELD CURRENT RANGE switch
S30 to X1 position. Plug phone plug into calibration jack for AC AMMETER OUTPUT CURRENT
meter M5, and connect plug leads to calibrating jacks of DC AMMETER FIELD CURRENT meter
M7. Set AC AMMETER OUTPUT CURRENT RANGE switch S26 to X1 position, and AC AMMETER
OUTPUT CURRENT SELECT switch S25 to T1 position. Connect test lead from positive DC
VARIABLE VOLTS OUTPUT binding post to ALTERNATOR T1 binding post, and connect another
test lead from rectifier chamber T1 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 D.C. VARIABLE
VOLTS switch S10 to ON position, and adjust DC VARIABLE POWER SUPPLY 0-32 VDC control
T5 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 meter
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 it is set back to ON position. Repeat check with AC AMMETER
OUTPUT CURRENT RANGE switch set to X5 position.
If DC AMMETER FIELD CURRENT meter M7 shows slight deflection but AC AMMETER
OUTPUT CURRENT meter M5 does not, replace meter M5. 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 current transformer CT1 and AC AMMETER OUTPUT CURRENT SELECT
switch S25, and replace defective part.
Step 2.
Set circuit breaker CB1 to OFF position. Leave DC VOLTMETER OUTPUT VOLTAGE SELECT
switch S11, DC VOLTMETER OUTPUT VOLTAGE RANGE switch S12, DC AMMETER
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