TM 9-4940-568-20
2-117
Table 2-21. Crane Troubleshooting (CONT).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 5.
Disconnect FRS to crane connector at hydraulic bulkhead. Check for 24VDC at pin
A of connector.
If 24 volts are present, go to Test 6.
If 24 volts are not present, the problem is with the FRS electrical system. Refer to
troubleshooting paragraph 2-13 in this manual.
NOTE
Reconnect harness at bulkhead.
Test 6.
Loosen four screws and clips and open crane junction box cover. Check for 24 volts
between junction box terminal strip, position 3, and a good ground.
If 24 volts are present, go to Test 7.
If 24 volts are not present, repair or replace white wire in connector from hydraulic
bulkhead to junction box terminal strip position 3. Refer to paragraph 3-16 in this
manual.
Test 7.
Check for 24 volts at crane main power switch (white wire).
If 24 volts are present, go to Test 8.
If 24 volts are not present, repair the white wire from the center terminal of the D-5
and D-6 diodes and the main power switch for the crane.
Test 8.
Check for 24 volts on the black wire terminal of the crane main power switch.
If 24 volts are present, go to Test 9.
If 24 volts are not present, replace crane main power switch.
