TM 5-5420-234-14&P
4-12. UNIT TROUBLESHOOTING (continued).
11. HOOK ARM DOES NOT LOAD IN MANUAL MODE (MODEL B ONLY) (continued).
NOTE
The digital controller and the cab control box are not repairable,
therefore, it is necessary to test the digital controller and cab
interface wiring harnesses, switches, solenoids, and other com-
ponents to identify possible faults other than the digital controller
and the digital cab controller.
14.
TEST OPTIONS
KNOWN INFO
Is there continuity
Error Code, EC 05 and/or
Continuity Tests.
measured at the hook
EC 17.
REASON FOR QUESTION
arm load valve
Remote control unit OK.
solenoid?
Remote control cable
If there is no continuity
OK.
at the designated
Cab digital control box
positions on the main
OK.
frame load valve
Cab interface wiring
solenoid, the 24 volt
harness OK.
power from the digital
Digital controller wiring
control box does not
harness OK.
activate the hook arm
load valve.
POSSIBLE PROBLEMS
Main frame load valve
solenoid faulty.
Digital control box faulty.
Repair or replace
NO
hook arm load
valve (para 5-25).
YES
If all previous
tests were
completed with a
satifactory result,
replace digital
control box (para
4-214.6
20
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