TM 9-4910-663-34
Table 2-5. TROUBLESHOOTING (Continued)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Replace defective switches. Repair wiring defects.
Step 3.
With circuit breaker switch CB1 set to ON position, momentarily press DC AMMETER LOAD &
STARTER OUTPUT CURRENT BATTERY CHARGE CURRENT PRESS FOR BATTERY CHARGE
RATE switch S15, and check to see that indications on external DC millivolt meter and DC
AMMETER LOAD & STARTER OUTPUT CURRENT BATTERY CHARGE CURRENT meter M3
both drop to zero momentarily.
If meter indications do not drop to zero momentarily, replace switch S15.
Step 4.
Set DC AMMETER LOAD & STARTER OUTPUT CURRENT BATTERY CHARGE CURRENT
RANGE switch S14 to X3 position, then to X10 position. Check to see that DC AMMETER LOAD &
STARTER OUTPUT CURRENT BATTERY CHARGE CURRENT meter M3 indicates 6 to 8 amperes
on appropriate scale for each switch position.
If meter indicates zero in either position, replace switch S14.
14.
AC VOLTMETER OUTPUT VOLTAGE METER CIRCUIT
a.
AC VOLTMETER OUTPUT VOLTAGE METER INOPERATIVE OR INDICATES INCORRECTLY DURING TEST OF
EXTERNAL COMPONENTS.
Step 1.
Set all controls to preliminary settings listed in table 2-2. Set AC VOLTMETER OUTPUT VOLTAGE
RANGE switch S27 to X1 position. Set DC VOLTMETER OUTPUT VOLTAGE SELECT switch S11
to VAR position, and DC VOLTMETER OUTPUT VOLTAGE RANGE switch S12 to X1 position.
Connect positive lead of external 0-50 volt DC voltmeter to right calibration jack (facing panel meter)
for AC VOLTMETER OUTPUT VOLTAGE meter M6, and negative lead of external DC voltmeter to
left calibration jack. Set AC VOLTMETER OUTPUT VOLTAGE SELECT switch S28 to CIRCUIT T1-
T2 position. Connect test lead between positive DC VARIABLE VOLTS OUTPUT binding post and
ALTERNATOR T1 binding post, and connect another test lead between negative DC VARIABLE
VOLTS OUTPUT binding post and ALTERNATOR T2 binding post. Make certain that DC
VARIABLE POWER SUPPLY 0-32 VDC control T5 is set fully counterclockwise. Set DC VARIABLE
VOLTS switch S10 to ON position, and adjust DC VARIABLE POWER SUPPLY 0-32 VDC control
2-50
