TM 5-5420-234-14&P
4-12. UNIT TROUBLESHOOTING (continued).
12. HOOK ARM DOES NOT UNLOAD IN MANUAL MODE (MODEL B ONLY) (continued).
VOLTAGE TEST
(1) Remove three thumb screws and
access cover on right side of vehicle
under front fender to gain access to
cab interrface wiring harness
connector.
ACCESS
(2) Cut and remove wire ties as
COVER
necessary to loosen cab interface
wiring harness.
(3) Set multimeter to voltage position.
(4) Turn engine start switch to ON
position.
(5) Place negative (-) probe of multimeter
on known good ground.
(6) Disconnect cab interface wiring
harness connector, (J2) from digital
P2
controller wiring harness connector,
J2
(P2).
(7) Place positive (+) probe of multimeter
on position "2", circuit 1473, of cab
control box connector (J2), Check
multimeter for voltage reading, note
reading.
(8) Place cab digital mode select switch
in "AUTO" position.
(9) Place positive (+) probe of multimeter
on position "3", circuit 1471, of cab
POSITION
control box connector (J2), note
4
POSITION
POSITION
reading.
2
3
NOTE
Position " 4", circuit 1490, should
have a reading of 1-5 volts, not
22-28 volts. If 1-5 volts are not
measured at position "4", replace
the cab digital control box.
(10) Place positive (+) probe of
multimeter on position "4", circuit
1490, of cab digital control box
connector (J2), note reading.
(11) Turn engine start switch to "OFF"
position.
CABDIGITAL
MODE SELECT
SWITCH
4-4-233
236.9
Change 1
