(1) Loosen screw and disconnect
solenoid connector, top half.
(2) Turn differential solenoid valve M51
manual override screw to the left and
listen for air passing through valve.
(a) If air does not pass through valve,
replace valve (Para 12-40).
(b) If air does pass through valve,
valve is OK.
(3) Turn solenoid valve M51 manual
override screw all the way to the right.
SOLENOID VALVE TEST
Remove all jewelry such as rings, dog tags, bracelets, etc. If jewelry or tools contact positive electrical
circuits, a direct short may result. Damage to equipment, injury or death to personnel may occur.
(1) Set multimeter select switch to volts
(2) Connect positive (+) multimeter lead
to differential lockup solenoid
connector, terminal 1.
(3) Connect negative () multimeter lead
to a known good ground.
(4) Turn ON ENGINE switch
(a) If 10 to 14 vdc are not present,
turn OFF ENGINE switch and go
to Step 5 of this Fault.
(b) If 10 to 14 vdc are present,
wire 1890 is OK.
(5) Turn OFF ENGINE switch.