TM 5-5420-234-14&P
4-12. UNIT TROUBLESHOOTING (continued).
12. HOOK ARM DOES NOT UNLOAD IN MANUAL MODE (MODEL A ONLY) (continued).
KNOWN INFO
8.
TEST OPTIONS
Continuity Test.
Does not operate with
Is there continuity
remote control or cab
measured on the (24-
REASON FOR QUESTION
controls.
pin) linking harness
Hook arm Unload
between cab control
During cab control opera-
solenoid harness OK.
box connector (P2)
tion, this harness provides
Main junction box wiring
and main junction box
power to the hook arm
OK.
connector (P4)?
UNLOAD solenoid. During
remote control operation,
POSSIBLE PROBLEMS
the harness provides a
signal to activate the free-
Linking harness faulty.
flow valve and close the
Directional control valve
transit valves.
faulty.
Replace (24-pin)
linking harness
NO
Directional control
valve is faulty; notify
YES
Direct Support
maintenance.
4-230
Change 1
