TM 5-3810-307-24-1-1
a.
If wheels turn as stated, proceed to step
a.
If 4WD operates as stated, 4WD is
3.
functioning properly. No further steps
are necessary.
b.
If front wheels turn with rear wheels,
b.
If front wheels do not turn at all, check
check wire 935 for 24 vDC at 4WD
wire 935 for 24 vDC at 4WD solenoid.
solenoid valve.
(1)
If 24 vDC is present, problem is in
(1)
If 24 vDC is not present, solenoid,
solenoid, solenoid valve, 4WD
solenoid valve, 4WD hydraulic
hydraulic circuit, or transmission.
circuit, or transmission is faulty.
Check and correct any fault(s) as
Check and correct any fault(s) as
necessary
and
recheck
necessary
and
recheck
operation.
operation.
(2)
If 24 vDC is not present, check
(2)
If 24 vDC is present, stop crane
2WD/4WD
electrical
circuit.
and proceed to step 4.
Correct any fault(s) and recheck
c.
If front wheels turn but do not disengage
operation.
after entering F4, stop crane, and
proceed to step 4.
3.
Idle engine and apply brakes. When wheels
are stopped, place DRIVE AXLE selector switch in
4.
Remove APC 100 fuse and relay box from cab
4WD position, position transmission shift lever to F4,
wall mounting, and remove cover from fuse and relay
release brakes, and accelerate so transmission will
box leaving APC 100 control box connected to relay
shift up to F4 gear. The front wheels should turn with
box harness (rectangular connector).
the rear wheels until transmission shifts from F3 to
F4. When this occurs, 4WD should disengage and
5.
Position ignition switch to 1 (run), place
front wheels should begin to slow.
transmission shift lever in F1, and check 4WD output
circuits for voltage during the various modes as
CAUTION
shown in Table 2-3-8.
Be sure to position drive axle selector
a.
Correct any faults in circuits that do not
switch to 2WD before decelerating. If
function as stated in table and recheck
selector switch is left in 4WD position,
circuit outputs.
4WD re-engagement will occur when
transmission shifts into F2. Damage
b.
If the voltage in wire 35 is not correct,
may occur if 4WD is allowed to engage
there is a fault in the EPROM or the APC
while wheels are turning at different
100 control box, see APC 100
speeds.
CONTROL
BOX
DIAGNOSTICS,
correct any fault(s), and recheck circuit
output.
Table 2-3-8. 2WD/4WD Output Circuit Voltages
CIRCUIT VOLTAGES
DRIVE AXLE SELECTOR
RELAY BOX MODE
SWITCH POSITION
WIRE
WIRE
WIRE
WIRE
WIRE
914
35
70
50
935
Automatic
2WD
24
24
24
24
0
Automatic
4WD
0
0
0
0
24
Automatic
4WD
24
24
24
24
24
Manual
2WD
0
0
0
24
0
Manual
4WD
0
0
0
0
24
2-3-35/(2-3-36 Blank)
