Electrical System Troubleshooting (Contd).
TEST OR INSPECTION
18. RCU WILL NOT LOCK LAUNCH BOOM INTO COUPLING POSITION (L14-A) AND (L15-A)
Step 1. Check that KY1, KY17, and KY23 hydraulic control valve solenoid LED lights are lit when
action button 1 is depressed.
Potentiometer JR2 is used to stop launch boom at a set position in
the launching procedures.
a. If all lights are lit on control valve solenoids, check potentiometer JR2 position 3 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 solenoid lights are lit, refer to
c. Check operation of IQAN-XP and IQAN-XS LED lights. Refer to WP 0004 00 step h.
Step 2. Check to see if only one or no lights are lit when action button 1 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
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 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
d. Check wire between KL-1 buss bar pin 1 and IQAN-XS connector pin 20. Replace wire if
e. Check wires between KL-1 buss bar pins 17, 23, 34, 35, and 48 and IQAN-XP connector
pins 34, 27, 15, 17, and 1. Replace wires if damaged. Refer to WP 0053 00.
END OF TESTING