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
13.
TEST OPTIONS
LHS OK using manual
Are 2228 volts mea-
Voltage Test.
controls.
sured on the socket for
Hook arm unloads OK.
REASON FOR QUESTION
Main frame fails to
The main frame unload
unload.
function is triggered by the
Hook arm up proximity
closing of relay K8, which
switch OK.
is controlled by a proximity
Main frame junction box
switch. If voltage is mea-
harness OK.
sured at relay K8 socket, it
Main LHS harness OK.
indicates that the signal
Main junction box wiring
voltage from the proximity
OK.
switch is reaching the
Linking harness OK.
relay.
POSSIBLE PROBLEMS
Relay K8 faulty.
Cab control box faulty.
Repair cab control
NO
Replace relay K8
YES
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