TROUBLESHOOTING (Continued)

TM 9-4910-663-34 Table 2-5. TROUBLESHOOTING (Continued) MALFUNCTION TEST OR INSPECTION CORRECTIVE ACTION VARIABLE LOAD control R32 at its fully clockwise position, check to see that DC AMMETER FIELD CURRENT meter M7 indicates approximately 6 to 8 amperes, and external DC millivolt meter indicates approximately 8 to 15 millivolts. If DC AMMETER FIELD CURRENT meter M7 indicates zero but indication on external DC millivolt meter is normal, replace DC AMMETER FIELD CURRENT meter M7. If neither DC AMMETER FIELD CURRENT meter M7 nor external DC millivolt meter indicate, but DC AMMETER LOAD & STARTER CURRENT BATTERY CHARGE CURRENT meter M3 indicates, proceed to step 2. If indications on all three meters are zero, proceed to step 3. If all meter indications are normal, proceed to step 4. Step 2. Set circuit breaker switch CB1 to OFF position. Using ohmmeter, perform continuity check of DC AMMETER FIELD CURRENT RANGE switch S30 and associated circuit. (See FO-1.) NOTE Disconnect leads from shunts R28, R29, and R30 as required when making continuity checks. Replace DC AMMETER FIELD CURRENT RANGE switch S30 if it is defective. Step 3. Set circuit breaker switch CB1 to OFF position. Using ohmmeter, perform continuity check of generator field circuit from REGULATOR F-B binding post to GENERATOR F binding post. (See FO-1.) Check for continuity across each contact of each switch, and across contacts of FINE CONTROL circuit breaker CB10. Replace any defective switch or circuit breaker. Repair wiring defects. Step 4. Disconnect external DC millivolt meter. Set DC AMMETER FIELD CURRENT RANGE switch S30 to X3 position. Adjust VARIABLE LOAD control R32 to provide 5 ampere indication on DC AMMETER FIELD CURRENT meter M7. 2-47