TM 5-5420-280-23&P
0008 00
Electrical System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
31. RCU WILL NOT RAISE NEAR-SHORE END OF BRIDGE WITH WINCH WIRE ROPE (R5-H) (CONTD)
Step 5. Check that KY1 and KY21 hydraulic control valve solenoid LED lights are lit when action
button 2 is depressed.
a. If all lights are lit on control valve solenoids, refer to malfunction 5 in Hydraulic System
Troubleshooting (WP 0010 00).
b. Check operation of IQAN-XP and IQAN-XS LED lights. Refer to WP 0004 00 step h.
Step 6. Check to see if one or more control valve solenoid LED lights are out when action button 2
is depressed.
a. If light is out, check for 24 volts at control valve solenoid.
b. If connector has 24 volts, replace control valve solenoid or hydraulic control valve. Refer
to WP 0075 00.
c. If connector has no voltage, check wires at KL-1 buss bar pin 1 for KY1 control valve
solenoid, KL-1 buss bar pin 21 for KY21 control valve solenoid, and KL-1 buss bar pin 29
for KA5 limit switch. Refer to Electrical System Schematic (WP 0122 00) and repair or
replace wires (WP 0053 00).
d. Check wire between KL-1 buss bar pins 1 and 21 and IQAN-XS connector pins 20 and 36.
Replace wires if damaged. Refer to WP 0053 00.
e. Check wire between KL-1 buss bar pins 3 and 29 and IQAN-XP connector pins 37 and 16.
Replace wires if damaged. Refer to WP 0053 00.
END OF TESTING
32. RCU WILL NOT RAISE FAR-SHORE END OF BRIDGE WITH LAUNCH BOOM (R6-A)
Step 1. Check that KY1, KY17, KY20, and KY23 hydraulic control valve solenoid LED lights are lit
when action button 2 is depressed.
NOTE
Potentiometer JR2 is used to stop launch boom at a set position in
the retrieval procedure.
a. If all lights are lit on control valve solenoids, check potentiometer JR2 position 2 to see if
damaged or out of adjustment. Adjust or replace potentiometer JR2. Refer to WP 0093 00.
b. If potentiometer JR2 is operating and control valve solenoids lights are lit, refer to
malfunction 7 in Hydraulic System Troubleshooting (WP 0010 00).
c. Check operation of IQAN-XP and IQAN-XS LED lights. Refer to WP 0004 00 step h.
Step 2. Check to see if one or more lights are out when action button 2 is depressed.
a. If light is out, check for 24 volts at control valve solenoid.
b. If connector has 24 volts, replace control valve solenoid or hydraulic control valve
c. If connector has no voltage, check wires at KL-1 buss bar pin 1 for KY1 control valve
solenoid, KL-1 buss bar pin 17 for KY17 control valve solenoid, KL-1 buss bar pin 20 for
KY20 control valve solenoid, KL-1 buss bar pin 23 for KY23 control valve solenoid, and
KL-1 buss bar pins 34, 35, and 48 for JR2 potentiometer. Refer to Electrical System
Schematic (WP 0122 00) and repair or replace wires (WP 0053 00).
d. Check wire between KL-1 buss bar pin 1 and IQAN-XS connector pins 20. Replace wires
if damaged. Refer to WP 0053 00.
e. Check wire between KL-1 buss bar pins 17, 20, 23, 34, 35, and 48 and IQAN-XP connector
pins 34, 40, 27, 15, 17, and 1. Replace wires if damaged. Refer to WP 0053 00.
END OF TESTING
