TM- 9-4910-663-34
Table 2-5. TROUBLESHOOTING (Continued)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
If resistance indication is not as specified, replace rheostat R32.
Step 4. Using ohmmeter, check for continuity across terminals of LOAD SELECTION 0-25 AMPS/0-12.5
AMPS switch S24.
Replace switch S24 if open indication is obtained.
Step 5. Using ohmmeter, check for continuity across contacts of relay K10.
If continuity indication is not obtained, proceed to step 6.
Step 6. Using DC voltmeter, check for 24 to 30 volts across coil of relay K10.
If no voltage indication is obtained, set circuit breaker switch CB1 to OFF position, and perform
continuity check of wiring in accordance with figure 2-4.
Step 7. Set circuit breaker switch CB1 to OFF position. Disconnect leads from one side of coil of relay K10,
and check for resistance of 290 ohms ±10% across coil terminals, using ohmmeter.
If resistance is not as specified, replace relay K10.
Step 8. With circuit breaker switch CB1 set to OFF position, reconnect lead disconnected in step 7. Using
ohmmeter, check for continuity across terminals of MASTER LOAD DISCONNECT switch S8.
Replace switch S8 if open indication is obtained.
Step 9. Set LOAD SELECTION 0-25 AMPS/0-12.5 AMPS switch S24 to OFF position. Set LOAD
SELECTION 25 AMPS/12.5 AMPS switch S23 to ON position. With circuit breaker switch CB1 set to
ON position, check resistance indication between REGULATOR B+ and REGULATOR B- binding
posts with ohmmeter. Resistance should be 1.14 ohms ±5%.
2-27
