MAIN
POWER
WHITE WIRE
TM 9-4940-568-20
2-140
Table 2-21. Crane Troubleshooting (CONT).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
4. HOIST DOES NOT RAISE WITH REMOTE CONTROL (CONT).
Test 7.
Connect the remote control cable to the remote control unit and remote control
hook-up connector on crane sub-frame. Turn MAIN POWER switch to ON position.
Check for 24 volts from controller harness, white wire, with controller lever in UP
position, to known good ground. Turn MAIN POWER switch OFF.
If 24 volts are not present, replace controller circuit card. Refer to paragraph 5-12 in
this manual.
If 24 volts are present, reassemble remote control unit and go to Test 8.
Test 8.
Loosen four screws and clips and open crane junction box cover. Turn MAIN
POWER switch and EMERGENCY STOP switch to ON position. Check for 24 volts
between terminal strip, position 15, and known good ground with hoist controller
held in the UP position. Turn MAIN POWER switch to the OFF position.
If 24 volts are not present, repair black wire between remote control hook-up
connector on crane sub-frame and junction box terminal strip. Refer to paragraph
3-16 in this manual.
If 24 volts are present, go to Test 9.
