TM 9-4910-663-34
Table 2-5. TROUBLESHOOTING (Continued)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
If open indication is obtained for either set of switch contacts, replace switch S21.
Step 21. Set LOAD SELECTION 50 AMPS/25 AMPS switch S21 to OFF position. Set DC AMMETER LOAD
& STARTER OUTPUT CURRENT BATTERY CHARGE CURRENT RANGE switch S14 to LOAD
X10 position. Set LOAD SELECTION 50 AMPS/25 AMPS switch S20 to ON position. Using
ohmmeter, check for 0.57 ohm ±5% indication between REGULATOR B+ AND REG ULATOR
B- binding posts.
If resistance indication is not as specified, proceed to step 22; if resistance indication is normal,
proceed to step 27.
Step 22. Set LOAD SELECTION 50 AMPS/25 AMPS switch S20 to OFF position. Using ohmmeter, check for
1.14 ohm ±5% indication between REGULATOR B- binding post and each of terminals 13 and 14 of
load bank.
If either resistance indication is not as specified, replace load bank element.
Step 23. Using ohmmeter, check for continuity across each set of contacts of LOAD SELECTION 50
AMPS/25 AMPS switch S20 with switch S20 set to ON position.
If open indication is obtained for either set of contacts, replace switch S20.
Step 24. Using ohmmeter, check for continuity across contacts of relay K7 with circuit breaker CB1 set to ON
position.
If continuity indication is not obtained, proceed to step 25.
Step 25. Using DC voltmeter, check for DC voltage between 24 and 30 volts across coil of relay K7.
If no voltage is indicated, set circuit breaker switch CB1 to OFF position, and perform continuity
check of wiring and DC AMMETER LOAD & STARTER OUTPUT CURRENT BATTERY CHARGE
CURRENT RANGE switch S14. Replace switch S14 if it is defective.
Change 1 2-30
