TM 5-5420-234-14&P
4-12. UNIT TROUBLESHOOTING (continued).
15. LHS DOES NOT OPERATE PROPERLY IN AUTO MODE (CAB ONLY)
(continued).
KNOWN INFO
15.
TEST OPTIONS
LHS OK using manual
Are 2228 volts mea-
Voltage Test.
controls.
sured on the main
Hook arm unloads OK.
frame junction box
REASON FOR QUESTION
Main frame fails to
terminal strip, posi-
To verify that proximity
unload.
tion 4?
switch supply voltage is
Hook arm up proximity
reaching the main frame
switch OK.
junction box from main
Hook arm up proximity
junction box.
switch LED out.
Power at main junction
box terminal strip.
POSSIBLE PROBLEMS
Hook arm up proximity
switch faulty.
Replace main frame
Main frame junction box
junction box harness
NO
harness faulty.
Replace hook arm
YES
up proximity switch
4-328
