HWH 400 Series User manual

LOW
VOLTS
FUSE
HORIZONTAL
VERTICAL 5 AMP.
ON
AUTOMATIC
LEVELING
AUTOMATIC
RETRACT
LEFT REAR LEFT FRONT
RETRACT
HOLD
EXTEND EXTEND
HOLD
RETRACT
RIGHT FRONT RIGHT REAR
RETRACT
HOLD
EXTEND
TO PREVENT DAMAGE FROM OVERHEATING DO NOT HOLD SWITCH
ON FOR MORE THAN TWO OUT OF EVERY FOUR MINUTES.
BLOCK FRAME SECURELY BEFORE
CHANGING TIRES OR WORKING UNDER VEHICLE.
CAUTION!
MASTER
EMERGENCY
OFF
MANUAL OPERATION
H
HW
CORPORATION
R
ML7879/MI91.0009
12JAN06
HWH COMPUTER-CONTROLLED
HYDRAULIC LEVELING SYSTEM
400 SERIES
FEATURING:
Paddle Switch Control
SERVICE MANUAL
HWH CORPORATION
(On I-80, Exit 267 South)
2096 Moscow Road | Moscow, Iowa 52760
Ph: 800/321-3494 (or) 563/724-3396 | Fax: [phone]
www.hwh.com
R
CORPORATION
W
HH
R

SECTION 1
MI91.1015
18JUN01
SECTION
2
REPAIR STEPS
SECTION
3
DIAGRAMS
SECTION
1
TROUBLE
SHOOTING
STEPS
3 PART FOLDER
HOW TO USE MANUAL
PROCEED WITH TROUBLE SHOOTING GUIDE
This manual is written in three sections. Section 1 is the Trouble Shooting Steps. Section 2 is the Repair Steps. Section 3 is
the Diagrams. Begin diagnosis of the system with Section 1, the Trouble Shooting Steps. This will give the correct operation
and function of the system. When a malfunction is encountered, the Trouble Shooting Steps will direct you to the proper Repair
Steps in Section 2, the Repair Steps. The Repair Steps are broken into 3 columns, Problem, Solution, and Diagram. In the
proper part under Problems, find the symptom you have encountered. The testing and repair for that problem is in the Solu-
tion (center) column. Diagrams for a particular Problem and Solution are in the Diagram (right hand) column. This column will
direct you to the proper diagram in Section 3, Diagrams, for a more detailed view.
Before beginning your repair, it is IMPORTANT to read the CAUTIONS and NOTES AND CHECKS in the first section, TROUBLE
SHOOTING STEPS. In many cases this will save time and mistakes when trouble shooting a system.
This Repair Manual is offered as a guide only. It is impossible to anticipate every problem or combination of problems. This
manual is written in sequential order of the proper operation of the system. The Trouble Shooting Steps must be followed in
order to give correct diagnosis of the problem(s). For any problems encountered that are not addressed in this manual, contact
HWH Corporation for assistance.
NOTE: Diagrams in this manual are of typical systems. There may be plumbing or harness differences. In most cases
this should not effect trouble shooting procedures.

TROUBLE SHOOTING
MI91.1060
21APR11
NOTES AND CHECKS
Read and check before proceeding with Trouble Shooting Steps.
NOTE: HWH CORPORATION ASSUMES NO LIABILITY
FOR DAMAGES OR INJURIES RESULTING FROM THE
INSTALLATION OR REPAIR OF THIS PRODUCT.
The Trouble Shooting Guide must be followed in order. Prob-
lems checked for in one step are assumed correct and not
checked again in following steps.
2.
retracted position.
JUMPER WIRES(UP TO 10 GAUGE)
PRESSURE GAUGE(3500 PSI MIN.)
MULTI-METER
12 VOLT TEST LIGHT
PROCEED WITH THE TROUBLE
SHOOTING STEPS ON THE
FOLLOWING PAGE
Check that the oil reservoir is full with the jacks in the fully
1.
4. Proper grounding of all components is critical. See the elec-
trical circuit for specific grounds required. Faulty grounds, es-
pecially for the control panel, solenoid manifold or the pump
assembly, may cause control panel component damage and/or
improper or erratic operation.
5. Do not replace the control panel unless the Repair Steps say
to replace it. Otherwise the malfunctions may damage the new
control box.
This manual is intended for use by experienced mechan-
ics with knowledge of hydraulic and automotive electrical
systems. People with little or no experience with HWH lev-
eling systems should contact HWH technical service at
(800-321-3494) before beginning. Special attention should
be given to all cautions, wiring, and hydraulic diagrams.
Special note: When installing a new control panel, make
sure the panel is properly grounded before applying power
to the system.
Suggested tools for trouble shooting the HWH leveling systems:
existing hose end, tighten the hose end to snug plus 1/4
tighten the hose end 1/3 turn (2 FLATS). If tightening an
make the hose end snug (finger tight) on the fitting, then
Tightening of hose ends: If tightening a new hose end,
turn (1 FLAT).
WARNING!
BLOCK FRAME AND TIRES SECURELY BEFORE CRAWLING UNDER VEHICLE. DO NOT USE THE LEVELING
JACKS OR AIR SUSPENSION TO SUPPORT VEHICLE WHILE UNDER VEHICLE OR CHANGING TIRES. VEHICLE
MAY DROP AND OR MOVE FORWARD OR BACKWARD WITHOUT WARNING CAUSING INJURY OR DEATH.
WHEN ROUTING OR REROUTING HYDRAULIC HOSES AND WIRES, BE SURE THEY ARE NOT EXPOSED TO ENGINE
EXHAUST OR ANY HIGH TEMPERATURE COMPONENTS OF THE VEHICLE.
THE JACKS MAY ABRUPTLY SWING UP WHEN THE FOOT CLEARS THE GROUND OR WHEN THE JACK REACHES
NEVER PLACE HAND OR OTHER PARTS OF THE BODY NEAR HYDRAULIC LEAKS. OIL MAY CUT AND
SAFETY CLASSES ARE TO BE WORN TO PROTECT EYES FROM DIRT, METAL CHIPS, OIL LEAKS, ECT. FOLLOW
DO NOT OVER EXTEND THE REAR JACKS. IF THE WEIGHT OF THE VEHICLE IS REMOVED FROM ONE OR BOTH
REAR WHEELS, THE VEHICLE MAY ROLL FORWARD OR BACKWARD OFF THE JACKS.
FULL EXTENSION.
PENETRATE THE SKIN CAUSING INJURY OR DEATH.
ALL OTHER SHOP SAFETY PRACTICES.
3. Most coaches have more than one battery; one for the engine
and the other(s) for the coach. The engine battery supplies
power for the control box and hydraulic pump. DO NOT use
the coach batteries to supply power to the pump. Batteries
under no load should read 12.6 volts. Batteries must maintain
good voltage under load. Batteries must be in good condition
with no weak cells. An alternator, converter or battery charger
will not supply enough power for the system to operate properly.

TROUBLE SHOOTING STEPS
MI91.1065
17MAR98
LOW
VOLTS
FUSE
HORIZONTAL
VERTICAL 5 AMP.
ON
AUTOMATIC
LEVELING
AUTOMATIC
RETRACT
LEFT REAR LEFT FRONT
RETRACT
HOLD
EXTEND EXTEND
HOLD
RETRACT
RIGHT FRONT RIGHT REAR
RETRACT
HOLD
EXTEND
TO PREVENT DAMAGE FROM OVERHEATING DO NOT HOLD SWITCH
ON FOR MORE THAN TWO OUT OF EVERY FOUR MINUTES.
BLOCK FRAME SECURELY BEFORE
CHANGING TIRES OR WORKING UNDER VEHICLE.
CAUTION!
MASTER
EMERGENCY
OFF
MANUAL OPERATION
H
HW
CORPORATION
R
AUTOMATIC "LEVELING"
& "RETRACT" SWITCH
SYSTEM ON LIGHT
MASTER ON/EMERGENCY OFF
SWITCH
LOW VOLTS LIGHT
(OPTIONAL)
INDIVIDUAL JACK CONTROL
SWITCHES (4)
WARNING LIGHTS
(4 Red)
AUTOMATIC LEVELING
LIGHT
"HORIZONTAL/VERTICAL"
SWITCH
CONTROL FUSE
(5 AMP)
AUTOMATIC RETRACT
LIGHT
LEVELING LIGHTS
(4 Yellow)
1. Make sure the transmission is in the proper position for park-
ing and the park brake is set. With the ignition switch off, no
lights on the leveling system panel should be on. If any lights
are on, see Part 1 of the Repair Steps.
2. Turn the ignition switch to the ACC or ON position. The con-
trol panel should remain off. If any control panel lights come
on see Part 2 of the Repair Steps.
NOTE: The red warning lights will come on when the control
panel is off if a jack is extended and the ignition is on.
3. Push the "MASTER" switch to "ON". Some panels have a
two position switch. Some panels have a three position mo-
mentary switch. The system on light should come on. One or
two yellow lights may come on. If the pump starts running or
anything else occurs see Part 3 of the Repair Steps.
NOTE: If the vehicle is equipped with straight-acting jacks,
proceed to Step 5.
4. Push and hold the "HORIZONTAL/VERTICAL" switch to
"VERTICAL". The pump should come on. The four jacks should
drop and stay in the vertical position. The red warning lights
should come on. The pump should shut off when the switch
is released. If this is not so, see Part 4 of the Repair Steps.
5. Push each individual JACK CONTROL switch to "EXTEND".
These are momentary switches and the jack will stop extend-
ing when the switch is released. If the vehicle has straight-
acting jacks, the respective red light for each jack should
come on when the jack is extended 2 or more inches.
Make sure each jack will extend to the ground, lift the coach
and remain extended when the switch is released. Be care-
full not to twist the vehicle frame while performing this test. Lift-
ing with two jacks at a time will help reduce frame twist. If the
jacks do not extend properly, see Part 5 of the Repair Steps.
6. The yellow lights on the "RETRACT" side of the jack control
switches are the level indicator lights. A lit yellow light indicates
that corner or the vehicle is low. When all 4 yellow lights are
out, the vehicle should be level. Use 2 control switches at a
NOTE: Extending the jacks in pairs, two front, two side, or two
rear, will lift the vehicle without twisting the frame.
Check that the vehicle is level with all four yellow lights out. If
the yellow lights are not working properly see Part 6 of the Repair
Steps.
NOTE: SOME SYSTEM HAVE A REMOTE "MASTER" AND "AUTOMATIC LEVEL/RETRACT" SWITCH PANEL.
time to make sure all 4 yellow lights will come on at different
times.

AUTOMATIC LEVELING
MI91.1070
18MAR98
AUTOMATIC RETRACT
TROUBLE SHOOTING STEPS
CONTINUED
7. Push the jack control switches to RETRACT. The foot of
the jack will retract while the switch is being pushed. Kick-down
jacks should stay in the vertical position.
For straight-acting jacks, the red warning light will go out when
the jack is extended less than 2 inches.
The jacks cannot retract if the pump is running. Anytime the
pump is running when the panel is on and a switch is NOT being
pushed, refer to Part 3d of the Repair Steps.
If a jack will not retract when the control switch is pushed to re-
tract, see Part 7 of the Repair Steps.
8. For kick-down jacks, push and hold the H/V switch to hori-
zontal. The jacks should return to the horizontal position. The
red warning lights will go out as the jacks swing horizontal. If
this does not happen, see Part 8 of the Repair Steps.
IMPORTANT: Anytime the master switch is turned off or the
ignition switch is turned to another position, the microprocessor
is reset. Any automatic procedure in progress must be restart-
ed.
9. Turn the ignition switch to the ACC or ON position. Push the
master switch to ON. If the system does not turn on, return to
Part 3 of the Trouble Shooting Steps. Push the Automatic switch
to AUTOMATIC LEVELING. The following should occur:
For systems with straight-acting jacks, proceed to Step 10.
a. The automatic leveling light will start to blink.
b. The pump will come on.
c. The jacks will drop to the vertical position.
d. The pump will shut off several seconds after the jacks
are vertical.
e. The red warning lights will be on.
f. The automatic leveling light should glow steady.
If any of this does not occur, see Part 9 of the Repair Steps.
10. Push the AUTOMATIC LEVELING switch to AUTOMATIC
a second time. (For straight-acting jacks push the AUTOMATIC
LEVELING switch to LEVELING the first time.) The following
should occur:
a. The automatic leveling light will start to blink.
b. For systems with automatic air dump, the air will start
to dump from the vehicle suspension. After approxi-
mately 30 seconds, the system will start to level the ve-
hicle.
c. The jacks will extend according to lit yellow leveling lights.
d. For systems with straight-acting jacks. The red warning
lights will come on as the jacks extend 2 or more inches.
e. After all yellow lights go out, the system will pause then
stabilize the vehicle. Depending on the system, the pump
will run for a specific amount of time then shut off.
a. 20 seconds for most systems.
b. 10 seconds for systems with air dump.
jacks.
11. Push the master switch to "ON". Push the automatic switch
to "Retract". The following should occur:
a. The red automatic retract light should start to blink.
b. The jacks should retract. Kick-down style jacks will re-
turn to the horizontal position.
c. The individual red warning lights will go out.
d. Four minutes after the last warning light goes out, the
automatic retract light will go out and the panel will shut
off.
NOTE: Systems without the automatic off feature will have
to be turned off manually.
If any of the above does not occur, see Part 11 of the Repair
Steps.
c. 60 seconds for Blue Bird coaches with straight-acting
NOTE: Systems with 2 position master switches must be
turned off manually.
If any of the above does not occur, see Part 10 of the Repair
Steps.
f. The automatic leveling light will stop blinking and the
control panel will shut off.
At this time it is assumed that the system works correctly
in the manual mode. Any time the pump runs with the panel
on and no switches being pushed, refer to Part 3d of the
Repair Steps. Proceed with checking the system in the auto-
matic mode.

HWH CORPORATION
2096 MOSCOW ROAD/P.O. BOX 0183
MOSCOW, IOWA 52760-0183
800-321-3494 / 319-724-3396
ML7879/MI91.2120
16APR98
LEVELING SYSTEMS
FEATURING:
HWH COMPUTER-CONTROLLED
PADDLE SWITCH CONTROL
KICK-DOWN JACKS
BEGIN WITH SECTION 1
SECTION 2
OR
REPAIR MANUAL
400 SERIES
INTERNET: http: //www.hwhcorp.com
STRAIGHT-ACTING JACKS
OPTIONAL AUTOMATIC SUSPENSION AIR DUMP

REPAIR STEPS
SOLUTION DIAGRAMS
PROBLEM
MI91.2125
16APR98
REFER TO MP85.3455
REFER TO MP85.3455
REFER TO MP85.3455
Part 1
With the ignition
switch off:
a. The control panel
has lights on.
There should be no power on pin #1 of the control panel. Trace the
wire to its source. The wire should be connected to the ACC side of
the ignition switch.
Part 2
With the ignition
switch in the ACC
or ON position and
the control panel
off:
a. The system ON
light is lit.
If the control panel has a two position master switch, make sure the
switch is in the "OFF" position. If the light remains on, the control panel
should be repaired or replaced. REFER TO MI91.1065
b. A red warning
light is lit and no
jacks are extended
Unplug the wires to the JACK WARNING LIGHT pins. If the warning
light does not go out, replace the panel.
If the warning light goes out, plug the wires back in and disconnect the
jack warning switch from the harness. If the light goes out replace the
switch. If the light does not go out, the harness wire is shorted to ground
and should be repaired.
Part 3
With the MASTER
switch "ON":
a. The system on
light will not come
on. No other lights
come on and the
system will not func-
tion.
Check the 5 amp fuse in the control panel.
HORIZONTAL
MANUAL OPERATION
OFF
ON
MASTER
EMERGENCY
VOLTS
LOW
AUTOMATIC
LEVELING
AUTOMATIC
RETRACT VERTICAL
#1 +12 ACC. TERMINAL
5 AMP
EXTEND
HOLD
RETRACT
ON FOR MORE THAN TWO OUT OF EVERY FOUR MINUTES.
TO PREVENT DAMAGE FROM OVERHEATING, DO NOT HOLD SWITCH
WORKING UNDER VEHICLE. MANUAL USE LIMITED TO 4 MIN. WITHOUT COOL DOWN
BLOCK FRAME SECURELY BEFORE CHANGING TIRES OR
LEFT REAR
CAUTION!
LEFT FRONT
RETRACT
RIGHT FRONT
RETRACT
HOLD
EXTEND
HOLD
EXTEND
RIGHT REAR
CONTROL PANEL
CAUTION!
WORKING UNDER VEHICLE. MANUAL USE LIMITED TO 4 MIN. WITHOUT COOL DOWN
RIGHT REAR
BLOCK FRAME SECURELY BEFORE CHANGING TIRES OR
TO PREVENT DAMAGE FROM OVERHEATING, DO NOT HOLD SWITCH
MANUAL OPERATION
CONTROL PANEL
EXTEND
RETRACT
ON FOR MORE THAN TWO OUT OF EVERY FOUR MINUTES.
EXTEND
HOLD
RETRACT
LEFT REAR LEFT FRONT
EMERGENCY
ON
LOW
VOLTS
OFF
MASTER LEVELING
RETRACT
AUTOMATIC
AUTOMATIC
RIGHT FRONT
HOLD
RETRACT
HOLD
EXTEND
VERTICAL
HORIZONTAL
5 AMP
#12 RF
#11 LF
#10 LR
#13 RR
REFER TO MP85.3454
JACK
WARNING
LIGHT
LOW
VOLTS
FUSE
HORIZONTAL
VERTICAL 5 AMP.
ON
AUTOMATIC
LEVELING
AUTOMATIC
RETRACT
LEFT REAR LEFT FRONT
RETRACT
HOLD
EXTEND EXTEND
HOLD
RETRACT
RIGHT FRONT RIGHT REAR
RETRACT
HOLD
EXTEND
TO PREVENT DAMAGE FROM OVERHEATING DO NOT HOLD SWITCH
ON FOR MORE THAN TWO OUT OF EVERY FOUR MINUTES.
BLOCK FRAME SECURELY BEFORE
CHANGING TIRES OR WORKING UNDER VEHICLE.
CAUTION!
MASTER
EMERGENCY
OFF
MANUAL OPERATION
H
HW
CORPORATION
R
SYSTEM ON LIGHT
"MASTER/EMERGENCY"
SWITCH
RF
WARNING
SWITCH
MANUAL OPERATION
TO PREVENT DAMAGE FROM OVERHEATING, DO NOT HOLD SWITCH
BLOCK FRAME SECURELY BEFORE CHANGING TIRES OR
RIGHT REAR
WORKING UNDER VEHICLE. MANUAL USE LIMITED TO 4 MIN. WITHOUT COOL DOWN
MASTER
OFF
VOLTS
LOW
ON
EMERGENCY
LEFT REAR
CAUTION!
HOLD
ON FOR MORE THAN TWO OUT OF EVERY FOUR MINUTES.
RETRACT
EXTEND
AUTOMATIC
RETRACT
LEFT FRONT
RETRACT
EXTEND
HOLD
VERTICAL
EXTEND
RETRACT
RIGHT FRONT
HOLD
5 AMP
CONTROL PANEL
AUTOMATIC
LEVELING HORIZONTAL 5 AMP FUSE
#9 POSITIVE SIDE
If the fuse is not blown, check Pin 1 of the control panel or +12 volts.
Check Pin 2 for ground. If +12 and ground are present, the control
panel should be repaired or replaced. If +12 or ground is not present,
trace those wires to their source and repair. The ground should be a
good frame ground.
CONTROL PANEL
EXTEND
HOLD
RETRACT
WORKING UNDER VEHICLE. MANUAL USE LIMITED TO 4 MIN. WITHOUT COOL DOWN
TO PREVENT DAMAGE FROM OVERHEATING, DO NOT HOLD SWITCH
ON FOR MORE THAN TWO OUT OF EVERY FOUR MINUTES.
EMERGENCY
LEFT REAR
CAUTION!
OFF
VOLTS
MASTER
ON
LOW
#1 +12 ACC. TERMINAL
RIGHT FRONT
BLOCK FRAME SECURELY BEFORE CHANGING TIRES OR
VERTICAL
MANUAL OPERATION
HORIZONTAL
LEFT FRONT
RETRACT
EXTEND
HOLD
RETRACT
AUTOMATIC
LEVELING
AUTOMATIC
RIGHT REAR
RETRACT
HOLD
EXTEND
5 AMP
#2 BATTERY GROUND
REFER TO MP85.3455
or in the vertical
position.

REPAIR STEPS
SOLUTION DIAGRAMS
PROBLEM
MI91.2130
11JUN98
REFER TO MP85.3455
REFER TO MI91.1065
b. The system ON
light will not come
on. Leveling lights
will come on and
the system func-
tions.
The bulb may be burnt out. Remove the lens and use the clip under
the lens to remove the bulb. If a new bulb does not fix the problem,
the switch needs to be repaired.
c. Three yellow level-
ing lights or oppos-
ing leveling lights
come on. (Right
front and left rear
or left front and
right rear.)
Unplug the 5 wire sensing unit plug from the control panel. Use a test
light connected to ground to test the panel. Touch pins 4, 5, 6 and 7.
The appropriate light for that pin should come on. Only one light at a
time should come on. If the lights do not work properly, replace the
panel. If the panel works properly, replace the sensing unit.
REFER TO MP85.3460
If the fuse is blown, unplug the 11 pin harness, pins 14-24. Replace
the fuse and turn the master switch on again. If the fuse blows, check
that the wire connected to pin #9 is not shorted to ground. If pin #9 is
ok, replace the control panel.
If the fuse does not blow, continue with the repair. If the fuse blows when
the 11 pin harness is plugged in, there is a short in the master relay
circuit. Use the master and pump relay connection diagram for the
following tests.
Unplug connection A. Replace the fuse and turn the master switch on.
If the fuse blows, the red wire in the control harness is shorted to ground.
If the fuse does not blow, unplug connection B then plug in connection
A. If the fuse blows, replace the fuse board. If the fuse does not blow,
disconnect the red wire from Terminal 2 of the master relay. Plug in
connection B. With the panel ON if the fuse blows, the red wire in the
pump harness is shorted to ground. If the fuse does not blow, replace
the master relay.
If the fuse does not blow, plug the 11 pin harness back into the panel.
REFER TO MP85.3455
Part 3a continued

REPAIR STEPS
SOLUTION DIAGRAMS
PROBLEM
MI91.2132
11JUN98
REFER TO MP85.3460
Part 4
While pushing the
horizontal/vertical
switch toward ver-
tical:
a. The pump will
not run.
Use the master and pump relay connection diagram for this test. Con-
nect a test light to Terminal 3 of the master relay. With the control panel
"ON", check Terminals 1, 2, 4, 5 and 7 of the master and pump relays.
The control panel must be ON, the H/V switch does not have to be
pushed.
If there is no power at Terminal 1
inal 3 is tight, clean and not corroded. Check that the wire to Termin-
check that the connection at Term-
al 3 is good and has a solid, clean ground connection. This is ground
for the master relay. If not, fix those connections. If there is a good
ground to Terminal 3 and no power on Terminal 1, check the connec-
tion at Terminal 1. Check the battery connections and battery voltage.
Check the battery ground. Terminal 1 must have a good +12 volt supply
from the battery. Make sure the pump has a good solid, clean frame
mounting or connection.
REFER TO MP85.3460
REFER TO MP85.3466
Part 3 continued
d. The pump runs. Use the master and pump relay connection diagram for this repair. Dis-
connect the gray wire from Terminal 6 of the pump relay. Turn the sys-
tem on. If the pump runs, replace the pump relay. If the pump does
not run, reconnect the gray wire. With the system on, if the pump does
not run, the pump relay was stuck. Check and clean all connections
and check battery voltage. Low battery voltage or corroded connec-
tions can cause a relay to stick. If the pump runs with the panel on,
turn the panel OFF. Unplug connection B. Use a jumper to connect
Terminal 1 and Terminal 2 of the master relay. If the pump runs, the
gray wire in the pump harness is shorted to ground. If the pump does
not run, unplug connection A and plug in connection B. With Termin-
als 1 and 2 jumped together, the pump runs, replace the fuse board.
If the pump does not run, unplug the 11 pin plug from the control panel.
Plug in connection A. With Terminals 1 and 2 jumped together, the
pump runs, the gray wire in the control harness is shorted to ground.
If the pump does not run, replace the control panel.
e. The air starts to
exhaust from the
vehicle suspension.
Unplug connection C at the fuse panel. Turn the master switch on again.
If air exhausts from the suspension, replace the fuse panel (breaker
board). If air does not exhaust from the suspension, check that the
black wire for the air dump in the control harness is not shorted to the
red wire in the control harness. If the harness is ok, replace the control
panel.

REPAIR STEPS
SOLUTION DIAGRAMS
PROBLEM
MI91.2134
11MAY98
If there is power at the main stud of the fuse board, unplug the 11 pin
plug from the control panel. Ground the gray wire in the plug. If the
pump runs, replace the control panel. If the pump does not run, un-
plug connection A. Ground the pin for the gray wire in the male plug.
If the pump runs, the gray wire in the control harness is bad. If the pump
Each jack has an actuator that forces the jack into the vertical posi-
tion. The actuator pushes against a roller bearing or bushing. Each
jack also has a horizontal stop. Make sure the stops are in place and
properly adjusted. Make sure the roller bearing or bushing is in place
and turns freely. Make sure the jack can be pulled into the vertical
position. Hydraulically, all four actuators are connected to the same
REFER TO MP65.3455
b. One jack will not
swing vertical. The
pump does run.
+ + + +
RIGHT
REAR
RIGHT
FRONT
LEFT
LEFT FRONT
REAR
STAB. H/V
does not run, unplug connection B. Ground the pin for the gray wire in
the male plug. If the pump runs, replace the fuse board. If the pump does
not run, the gray wire in the pump harness is the problem and must be fixed.
LEFT
FRONT RIGHT FRONT
LEFT
REAR LEFT REAR
Part 4a continued If there is no power at Terminal 2,
check pin 14 at the control panel.
If there is no power at pin 14, replace the control panel. If there is power
at pin 14, there is a problem with connection A or B or with the red wire
in the control harness or pump harness.
If there is no power at Terminal 4, check the connection at Termin-
al 3. Make sure it is a good ground. If the ground is good, replace the
master relay.
If there is no power at Terminal 5 or 7, there is a problem with the
wires between Terminal 4 and Terminal 5 or 7 or the connections at
those terminals need to be fixed.
If there is no power on Terminal 8, connect the test light to Term-
inal 1 to check Terminal 6 for ground while the switch is being push-
ed. If Terminal 6 has a ground and Terminal 8 has no power, replace
the pump relay.
If there is power on Terminal 8, check Terminal 9 on the pump motor
for power. If Terminal 9 has power, check that the pump has a good
frame ground. If the pump ground is ok, the pump motor needs to be
rebuilt or replaced. If Terminal 9 has no power, the cable between Term-
inals 8 and 9 or the connections at Terminals 8 and 9 need to be
fixed.
If there is no ground to Terminal 6 while the H/V switch is being
pushed to "VERTICAL", there is a problem between the gray wire
If Terminals 1, 2, 4, 5, and 7 have power, check Terminal 8 of the
pump relay while the Horizontal/Vertical switch is being pushed
to "VERTICAL".
manifold valves. Check the fluid level in the reservoir. With all the jacks
completely retracted, the fluid should be within one inch of the top of
the reservoir.
at Terminal 6 and the control panel. Use a jumper wire to ground Term-
inal 6 with the control panel ON to make sure the pump will run. Turn
the panel "OFF". Use a jumper wire between Terminal 1 and 2 of the
master relay to turn that relay on. Check for power at the main stud
of the fuse board. If there is no power, there is a problem with the #10
black wire or its connections at the main stud or Terminal 4 of the master
relay.

REPAIR STEPS
SOLUTION DIAGRAMS
PROBLEM
MI91.2137
11MAY98
REFER TO MP85.3462
e. The jacks do
not swing vertical,
one or more jacks
extend in the hor-
izontal position.
The foot of the
jack(s) retract after
the H/V switch is re-
leased.
Unplug the solenoid valve for the jack that is extending in the horizon-
tal position. Plug that connector onto a solenoid valve that is not ex-
tending. Push the H/V switch to VERTICAL. If the problem changes
to a different jack, the control panel or the harness is the problem. If
the jacks swing vertical and no jacks extend, the valve that is unplug-
ged should be replaced.
f. The jacks do not
swing vertical, all
four jacks extend
in the horizontal
position.
Unplug the stabilize solenoid valve. Push the H/V switch to vertical.
If the jacks go vertical, check for power between the purple and red
wire in the stabilize plug. If power is present while pushing the H/V
switch, the problem is the control harness or the control panel. If power
is not present, replace the stabilize valve. If the jacks still extend in the
horizontal position with the stabilize valve unplugged, replace the sta-
bilize valve. REFER TO MP65.3452
GREEN
BLUE
BROWN
ORANGE
BA BA BA BA
BA
STAB.
PURPLE
BA
Part 4 continued
Unplug the H/V valve. With the system on, check for +12 on the red
wire in the female plug.
If +12 is not present, check the fuse at the fuse board for that valve.
Two valves are connected to each fuse. (Older fuse boards have
3 circuit breakers and some older boards have 2 circuit breakers
with 3 valves connected to each breaker.) If the fuse is blown (or
breaker is tripped) replace the fuse. (Let the breaker reset.) With the
system ON (leave the H/V valve unplugged) if the fuse blows again
or the breaker will not reset, the other valve connected to that fuse
(breaker) should be replaced. If the fuse does not blow, plug the H/V
valve back in. With the system on, if the fuse blows or the breaker
trips, replace the H/V valve.
If +12 is present on the red wire, check for ground on the yellow
wire in the plug while pushing the H/V switch to vertical. A test light
can be connected to the main stud on the fuse board to check for ground.
Check that the fluid reservoir is properly filled. Remove the return line
at the pump. Unplug the H/V valve. Push the H/V switch to VERTICAL.
REFER TO MP65.3455
REFER TO MP85.3462
c. The pump runs
under load. No
jacks go vertical.
d. The pump runs
under no load. The
jacks will not go
vertical, no jacks
are extending.
If the yellow wire has a ground, replace the H/V valve. If not, the yellow
wire or control panel is bad.
If fluid flows from the return line, replace the shuttle valve. If no fluid
flows from the return line, plug the H/V valve back in and try again.
If fluid flows from the return line, replace the bleed valve. If no fluid
flows from the return line, check voltage to the pump. Connect a 5000
psi pressure gauge to the pressure port of the pump. If the pressure
is less than 3000 psi, the pump should be repaired.
REFER TO MP85.3462
REFER TO MP85.3300
A
B
VERT
HOR/
YELLOW
BA
BA
HORIZONTAL /
VERTICAL
*
RED
YELLOW
REFER TO MP85.3305
LEFT
FRONT
+ +
STAB.
REAR
LEFT
+ +
FRONT
RIGHT
H/V
REAR
RIGHT
SHUTTLE
VALVE
RETURN
LINE
BA
HOR/
VERT
A
B
YELLOW

REPAIR STEPS
SOLUTION DIAGRAMS
PROBLEM
MI91.2139
11MAY98
REFER TO MP65.3455
Remove the return line from the pump. Push a jack control switch to
extend. If fluid flows out of the return line, replace the shuttle valve.
If no fluid flows from the return line, check voltage to the pump motor
while it is running. Low voltage will cause low pump pressure. Con-
nect a 5000 psi pressure gauge to the pressure fitting at the pump. If
there is less than 3000 psi while the pump is running, the pump should
be repaired. Remember to check the fluid level in the reservoir.
STAB.
LEFT
REAR
+
RIGHT
FRONT
FRONT
LEFT
H/V
+ ++
RIGHT
REAR
SHUTTLE
VALVE
RETURN
LINE
CHECK
VALVES (4) ADJUSTABLE
RELIEF
VALVE
PRESSURE
LINE
BREATHER
CAP
(OIL FILL)
PUMP
Part 4 continued
REFER TO MP85.3454
g. The jacks swing
vertical but retract
to the horizontal
position when the
H/V switch is re-
leased.
Push the H/V switch to VERTICAL. After the jacks are vertical, push
the MASTER SWITCH TO OFF before releasing the H/V switch. If
the jacks stay vertical, replace the H/V valve. If the jacks still retract
to the horizontal position, remove the return line from the pump. While
pushing the H/V switch to vertical, watch the return line. If fluid flows
from the return line, replace the bleed valve cartridge. If that does not
fix the problem, replace the H/V valve and the shuttle valve.
The actuators for 16,000 lb jacks can cause this problem. If the above
solution does not fix the problem, disconnect the hydraulic line to one
of the 16,000 lb jacks and cap the line. Retry the H/V switch. If the
jacks stay vertical, replace the actuator for the jack that is disconnect-
ed. If the jacks still retract, replace the actuator for the remaining 16,000
lb jack. REFER TO MP65.3455
h. The red light for
a jack will not come
on when the jack
is vertical.
Ground the wire for that warning switch at the jack. If the light comes
on, check the ground for that switch. If the ground is OK, replace the
switch. If the light does not come on, unplug the warning light wire
Part 5
With an individual
jack control switch
pushed to
"EXTEND":
a. The pump does
not run.
If the vehicle is equipped with straight-acting jacks, refer to Part 4a.
Replace the use of the H/V switch with a jack control switch in the EX-
TEND position.
If the vehicle is equipped with kick-down jacks, it is assumed the pump
and relays work. Push the H/V switch to VERTICAL. If the pump runs,
but not when a jack control switch is pushed to EXTEND, the control
panel needs to be repaired or replaced. If the pump does not run when
the H/V switch is pushed, return to Part 4a of the Repair Steps.
STAB.
LEFT
REAR
+
RIGHT
FRONT
FRONT
LEFT
H/V
+ ++
RIGHT
REAR
SHUTTLE
VALVE
RETURN
LINE
SEE ELECTRICAL
CONNECTION
DIAGRAM
CONTROL PANEL
CONTROL
PANEL
b. For straight-
acting jacks.
from the control panel. Use a test light connected to ground to ground
the pin for the red light that does not work. If the light comes on, the
harness wire is bad. If the light does not come on, replace the bulb or
have the control panel repaired.
The pump runs.
The jacks will not
extend or will ex-
tend but not pick
up the vehicle.

REPAIR STEPS
SOLUTION DIAGRAMS
PROBLEM
MI91.2142
17APR98
REFER TO MP65.3462
If the jack does not retract, unplug the solenoid valve for that jack.
With the panel on, check for power between the 2 pins of the harness
plug for that jack. If power is present, the harness wire is shorted to
ground or the control panel is bad. If power is not present, replace the
solenoid valve.
GREEN
BLUE
BROWN
ORANGE
BA BA BA BA
Part 5 continued
REFER TO MP65.3455
REFER TO MP85.3300
c. The pump runs
under load. A jack
will not extend.
Check the fuse or breaker for that solenoid valve at the fuse (breaker)
panel. Check that there is +12 power on the main stud and the con-
nection terminals at the fuse (breaker) panel. If the fuse is blown,
unplug the valve that will not extend. Two valves will be connected
to each fuse (breaker). Replace the fuse or let the breaker reset. With
the system ON, if the fuse blows or breaker trips, replace the solenoid
valve that is connected to that fuse (breaker). If the fuse does not blow,
plug the unplugged valve back in. If the fuse blows, replace that sol-
enoid valve.
If the fuse is not blown, unplug the solenoid valve for the jack that
will not extend. While pushing the jack control switch to EXTEND, check
for power between the two pins of the harness plug. If power is not
present, the problem is the harness or the control panel. If power is
present, replace the solenoid valve.
d. More than one
jack extends when
a jack control switch
is pushed to "EX-
TEND".
If the system has kick-down jacks the problem is a short in the con-
trol harness or the control panel needs to be rebuilt.
If the system has kick-down or straight-acting jacks and all four
jacks extend,
switches are used, replace the check valve for the jack that lets all four
extend.
If the system has straight-acting jacks,
es. If the same jack extends no matter which switch is pushed,
replace the solenoid valve. NOTE: The wire for that valve in the con-
trol harness could be shorted to ground. Check for power between
the two pins in the plug for that valve while pushing another switch to
extend. If power is present, the wire is shorted. If not, replace the
solenoid valve.
If only one switch runs two jacks, the control panel should be repair-
ed.
REFER TO MP85.3462
when one switch is pushed but not when other control
e. A jack will not
stay extended when
the switch is re-
leased.
While pushing the jack control switch to EXTEND, push the MASTER
switch to "OFF". If the jack retracts, the problem is either the sol-
enoid valve or the check valve. Replace the solenoid valve. If that
does not fix the problem replace the check valve.
REFER TO MP65.3455
try all four jack control switch-
GREEN
BLUE
BROWN
ORANGE
BA BA BA BA
STAB.
LEFT
REAR
+
H/V
RIGHT
FRONT
FRONT
LEFT RIGHT
REAR
+ + +
VALVE
SHUTTLE
CHECK
VALVES (4)
FRONT
+
CHECK
VALVES (4)
REAR
LEFT
STAB.
LEFT
+ +
VALVE
SHUTTLE
H/V
FRONT
RIGHT
+
REAR
RIGHT
A B
A
BB A B A B A
BA AB
GRAY
RED
RIGHT REAR *
RIGHT FRONT *
LEFT FRONT LEFT
REAR *
HORIZONTAL /
VERTICAL
STABILIZE
ORANGE
GREEN
BLUE
BROWN
YELLOW
PURPLE
RED RED RED RED
RED RED
RED
#10 BLACK
RED
GRAY
TO PUMP
*
* *
MAIN STUD
GROUND WIRE

REPAIR STEPS
SOLUTION DIAGRAMS
PROBLEM
MI91.2144
01JUL98
Part 7
While pushing a
jack control switch
to RETRACT:
a. The pump is run-
ning. Refer to Part 3d of the Repair Steps.
REFER TO MP85.3455
REFER TO MP85.3454
REFER TO MP85.3455
REFER TO MP85.3455
Part 5 continued
f. For straight-
acting jacks.
red warning light
will not come on
when the jack is
extended 2 inches
or more.
Ground the warning switch wire at the jack. If the light comes on,
check the ground for the warning switch. If the ground is ok, replace
the warning switch.
If the light does not come on, unplug the warning light wires at the
control panel. Use a test light to ground the pin for the light that will
not come on. If the light comes on, the problem is the wire. If the light
does not come on, check the bulb. If the bulb is ok, repair or replace
the control panel.
Part 6
The yellow lights
will not work prop-
erly.
a. A yellow light will
not come on.
Unplug the sensing unit plug from the control panel. With the panel
on, use a test light to ground the pin for the yellow light that does not
work. If the light does not come on, check the bulb, then replace the
panel if the bulb is ok. If the light does come on, replace the sensing
unit.
b. No yellow lights
come on.
Unplug the sensing unit plug from the control panel. With the panel
c. Yellow lights will
not go out.
Unplug the sensing unit plug from the control panel. If the lights do
not go out, replace the control panel. If the lights go out, use a test
light to ground pins 4, 5, 6 and 7. If the lights do not work properly,
replace the panel. If the lights work ok, replace the sensing unit.
d. The vehicle is not
level with all the
yellow lights out.
Adjust the sensing unit according to the level sensing unit adjustment
sheet.
REFER TO MP85.9505
SEE ELECTRICAL
CONNECTION
DIAGRAM
CONTROL PANEL
CONTROL
PANEL
RETRACT
ON FOR MORE THAN TWO OUT OF EVERY FOUR MINUTES.
CAUTION!
EMERGENCY
MASTER
WORKING UNDER VEHICLE. MANUAL USE LIMITED TO 4 MIN. WITHOUT COOL DOWN
TO PREVENT DAMAGE FROM OVERHEATING, DO NOT HOLD SWITCH
LEFT REAR
OFF
ON
LOW
VOLTS
HOLD
EXTEND EXTEND
RETRACT
HOLD
RETRACT
HOLD
EXTEND
HORIZONTAL
CONTROL PANEL
RIGHT FRONT
VERTICAL
BLOCK FRAME SECURELY BEFORE CHANGING TIRES OR
MANUAL OPERATION
LEVELING
AUTOMATIC
LEFT FRONT
RETRACT
AUTOMATIC
RIGHT REAR
5 AMP
#3 COMMON
#4 LR
#5 LF
#6 RF
#7 RR
WHITE
GREEN
RED
BLUE
BLACK
LEVEL
SENSOR
ON FOR MORE THAN TWO OUT OF EVERY FOUR MINUTES.
TO PREVENT DAMAGE FROM OVERHEATING, DO NOT HOLD SWITCH
EXTEND
HOLD
EXTEND
HOLD HOLD
EXTEND
#3 COMMON
#7 RR
#5 LF
#6 RF
#4 LR
WORKING UNDER VEHICLE. MANUAL USE LIMITED TO 4 MIN. WITHOUT COOL DOWN
CONTROL PANEL
BLOCK FRAME SECURELY BEFORE CHANGING TIRES OR
LEFT FRONT
RETRACT
AUTOMATIC
LEVELING
AUTOMATIC
MASTER
EMERGENCY
CAUTION!
OFF
RETRACT
LEFT REAR
LOW
VOLTS
ON
MANUAL OPERATION
RIGHT REAR
RIGHT FRONT
RETRACT RETRACT
HORIZONTAL
VERTICAL 5 AMP SENSOR
LEVEL
BLACK
RED
BLUE
GREEN
WHITE
ON FOR MORE THAN TWO OUT OF EVERY FOUR MINUTES.
TO PREVENT DAMAGE FROM OVERHEATING, DO NOT HOLD SWITCH
EXTEND
HOLD
EXTEND
HOLD HOLD
EXTEND
#3 COMMON
#7 RR
#5 LF
#6 RF
#4 LR
WORKING UNDER VEHICLE. MANUAL USE LIMITED TO 4 MIN. WITHOUT COOL DOWN
CONTROL PANEL
BLOCK FRAME SECURELY BEFORE CHANGING TIRES OR
LEFT FRONT
RETRACT
AUTOMATIC
LEVELING
AUTOMATIC
MASTER
EMERGENCY
CAUTION!
OFF
RETRACT
LEFT REAR
LOW
VOLTS
ON
MANUAL OPERATION
RIGHT REAR
RIGHT FRONT
RETRACT RETRACT
HORIZONTAL
VERTICAL 5 AMP SENSOR
LEVEL
BLACK
RED
BLUE
GREEN
WHITE
SOLID MOUNTING SURFACE
SPRINGS (3)
SENSING UNIT
4" DIA. X 3/4" THICK SCREWS (3)
A
on, use a test light to ground pins 4, 5, 6, and 7. If the yellow lights come
on as they should, connect the test light to a +12 source. Check the
#3 pin (common). If the test light comes on the panel is ok, replace the
sensing unit. If the above test does not work, check the bulbs, then
replace the control panel if the bulbs are ok.

REPAIR STEPS
SOLUTION DIAGRAMS
PROBLEM
MI91.2152
11MAY98
b. The leveling light
comes on and blinks.
The pump runs ap-
proximately 2 seconds
and shuts off. The
jacks do not go
vertical.
Unplug the pressure switch. Retry Part 9. If the jacks go vertical, re-
place the pressure switch. If the same problem repeats itself, check
the pressure switch wires to make sure they are not shorted to ground.
If the wires are ok, replace the control panel.
REFER TO MP85.3462
NONC
A
B
BLACK
WHITE
BA
REFER TO MP65.3455
b. A jack will not re-
tract.
Try to extend the jack. If the jack will not extend, return to Part 5 of
the Repair Steps. If the jacks will extend, the solenoid valve and fuse
panel (breaker panel) are ok. Take the hose loose from the jack, if the
jack retracts, check the hose for kinks or restrictions. If the hose is ok,
replace the solenoid valve. If the jack does not retract, replace the jack
if it is a straight-acting jack. If it is a kick-down jack, remove the tube
between the jack and the actuator or loosen the actuator clamps on
the 16,000# jacks. If the jack retracts, replace the actuator. If the jack
doesn’t retract, replace the jack.
c. No jack will re-
tract. Try to extend the jacks.
If the jacks will not extend, return to Part
5 of the Repair Steps. If the jacks will extend, the solenoid valves
d. For straight-acting
jacks. A red warn-
ing light will not go
out when the jack
is retracted.
Refer to Part 2b of the Repair Steps.
Part 8
When the H/V switch
is pressed to HOR-
IZONTAL:
a. A jack will not re-
turn to the horizon-
tal position.
Check that the hose to the actuator is not kinked. Check that the roller
assembly is ok. Check that the jack pivot points are free. If this is ok,
replace the actuator. REFER TO MP65.3455
Part 9
After pushing the
Automatic Level-
ing switch to Level-
ing one time:
a. The Automatic
Leveling light will
not blink.
Replace the control panel.
STAB.
LEFT
REAR
+
H/V
RIGHT
FRONT
FRONT
LEFT RIGHT
REAR
+ + +
VALVE
SHUTTLE
CHECK
VALVES (4)
RIGHT
REAR
b. A red warning light
will not go out when
the jacks are in the
horizontal position.
Refer to Part 2b of the Repair Steps.
Part 7 continued
and fuse panel (circuit breaker panel) are ok. Check the return line
for kinks. If the return line is ok, replace the shuttle valve.

REPAIR STEPS
SOLUTION DIAGRAMS
PROBLEM
MI91.2154
11MAY98
Part 9 continued
e. The red lights do
not come on. Recheck Part 4h of the Repair Steps.
f. The automatic
leveling light will not
stay on.
Recheck the voltage to the panel. Check all grounds and connections.
Low voltage, bad grounds, or loose, corroded connections can cause
problems.
Part 10
After pushing the
Automatic Leveling
switch to leveling
the second time:
a. The leveling light
will not blink or blinks
but nothing happens.
A problem can occur at any time. For systems with kick-down jacks,
turn the panel off, then recheck Part 9 of the Trouble Shooting Steps.
If Part 9 checks ok, the control panel should be repaired.
For systems with straight-acting jacks, refer to Part 9a, b and c of the
Repair Steps. Replace "go vertical" with "extend".
REFER TO MP65.3455
c. The leveling light
comes on and blinks
for approximately
30 seconds. The
pump does not run.
The jacks do not go
vertical.
Recheck Part 4 of the Trouble Shooting Steps. If the system works
properly in the manual mode. The problem is probably the fuse board
(breaker board). Replace the fuse board. If that does not fix the prob-
lem, replace the control panel. Remember the manifold mounting and
pump mounting, supply grounds for the system and should be check-
ed for clean, tight connections to the vehicle frame.
REFER TO MP85.3460
d. The jacks go to
the vertical position
but the pump will not
shut off.
Unplug the pressure switch. Turn the system on and push the auto-
matic leveling switch to LEVELING. As the jacks go vertical, short
the two pins in the harness plug for the pressure switch together.
If the pump does not shut off, check the pressure switch wires in
the harness. If the pressure switch wires are ok, replace the control
panel.
If the pump shuts off,
REFER TO MP85.3462
LOW
VOLTS
VERTICAL
RIGHT FRONT
MANUAL OPERATION
HORIZONTAL
BLOCK FRAME SECURELY BEFORE CHANGING TIRES OR
WORKING UNDER VEHICLE. MANUAL USE LIMITED TO 4 MIN. WITHOUT COOL DOWN
TO PREVENT DAMAGE FROM OVERHEATING, DO NOT HOLD SWITCH
ON FOR MORE THAN TWO OUT OF EVERY FOUR MINUTES.
EMERGENCY
MASTER
CAUTION!
LEFT REAR
LEVELING
RETRACT
AUTOMATIC
AUTOMATIC
ON
OFF
LEFT FRONT
RETRACT
HOLD
EXTEND
RETRACT
EXTEND
HOLD
5 AMP
RIGHT REAR
RETRACT
HOLD
EXTEND
CONTROL PANEL
A B
#14 MASTER RELAY
RED
CONTROL HARNESS
2
MASTER
RELAY
RED
(+12 CONTROL)
PUMP
HARNESS
RED
CONNECTION A
CONNECTION B
RED
RED
FUSE
PANEL
BA
BA
NONC
WHITE
BLACK
SHIELDED
CABLE
RIGHT
REAR
PUMP
BREATHER
CAP
(OIL FILL) PRESSURE
LINE
RETURN
LINE
SHUTTLE
VALVE
check the return line to the pump while push-
ing the H/V switch to VERTICAL. If there is fluid flowing from the return
line, replace the shuttle valve. If no fluid flows from the return line, re-
move the pressure line from the pump and attach a 5000 psi gauge to
the pump fitting. Push the H/V switch to VERTICAL. If the pump pres-
sure is above 3000 psi, replace the pressure switch. If pump pressure
is below 3000 psi, check the voltage and ground for the pump. If that
is ok, have the pump rebuilt.

REPAIR STEPS
SOLUTION DIAGRAMS
PROBLEM
MI91.2157
16APR98
Part 10 continued
d. For straight-
acting jacks.
The red lights do
not come on as the
jacks extend.
Recheck Part 5f of the Repair Steps.
e. For straight-
acting jacks.
The pump runs ap-
proximately 2 sec-
onds then shuts off.
Refer to Part 9b of the Repair Steps.
f. The vehicle will
not level itself ac-
cording to the yellow
lights.
REFER TO MP85.3454
g. Jacks do not ex-
tend to stabilize the
vehicle. The pump
runs under a load.
The stabilize valve is not opening. Retract the jacks and unplug the
leveling sensing unit from the control panel. Unplug the stabilize valve
and plug the harness plug for the stabilize valve into one of the jack
control valves. Run the system through the automatic mode. With no
yellow lights on the system will go into the stabilize mode immediately.
If the jack that is connected to the stabilize plug extends, replace the
stabilize valve. If the jack does not extend, the problem is the control
panel. REFER TO MP85.3462
Retry the system in the manual mode. Check all connections, grounds
and voltage. The ground straps for the sensing unit and the pressure
switch wire are shielding cables. Poor grounds of these wires can cause
problems in the automatic mode. If everything is ok, the problem is in
the control panel.
GROUND
STRAP
TO FRAME
SENSING
UNIT
BA
STAB.
PURPLE
BA
c. For straight-
acting jacks.
The pump runs, but
nothing happens.
Recheck the system in the manual mode. If the system works manual-
ly but not automatically the control panel should be repaired.
b. For systems with
automatic air dump:
The automatic level-
ing light is blinking
but the air will not
exhaust from the
vehicle suspension.
Check that the manual shut off on the air dump valves are open and
that the dump ports are clear of debris. Make sure the grounds for the
dump valves are good connections and not corroded.
With the automatic leveling light blinking, check the black wire in the
control harness at connection A. If +12 is not present, check that the
black wire is not broken then replace the control panel.
If +12 is present at connection A, check the black wire from the fuse
panel at connection B. If +12 is not present, replace the fuse panel.
If +12 is present, the problem is the dump valves, their grounds or the
wiring from connection B to the valves.
REFER TO MP75.3453
REFER TO MP85.3466
LOW
VOLTS
VERTICAL
RIGHT FRONT
MANUAL OPERATION
HORIZONTAL
BLOCK FRAME SECURELY BEFORE CHANGING TIRES OR
WORKING UNDER VEHICLE. MANUAL USE LIMITED TO 4 MIN. WITHOUT COOL DOWN
TO PREVENT DAMAGE FROM OVERHEATING, DO NOT HOLD SWITCH
ON FOR MORE THAN TWO OUT OF EVERY FOUR MINUTES.
EMERGENCY
MASTER
CAUTION!
LEFT REAR
LEVELING
RETRACT
AUTOMATIC
AUTOMATIC
ON
OFF
LEFT FRONT
RETRACT
HOLD
EXTEND
RETRACT
EXTEND
HOLD
5 AMP
RIGHT REAR
RETRACT
HOLD
EXTEND
A B
ELECTRICAL
CONNECTION
DIAGRAM
HYDRAULIC
MANIFOLD
CONTROL HARNESS
CONNECTION A
LOW
VOLTS
VERTICAL
RIGHT FRONT
MANUAL OPERATION
HORIZONTAL
BLOCK FRAME SECURELY BEFORE CHANGING TIRES OR
WORKING UNDER VEHICLE. MANUAL USE LIMITED TO 4 MIN. WITHOUT COOL DOWN
TO PREVENT DAMAGE FROM OVERHEATING, DO NOT HOLD SWITCH
ON FOR MORE THAN TWO OUT OF EVERY FOUR MINUTES.
EMERGENCY
MASTER
CAUTION!
LEFT REAR
LEVELING
RETRACT
AUTOMATIC
AUTOMATIC
ON
OFF
LEFT FRONT
RETRACT
HOLD
EXTEND
RETRACT
EXTEND
HOLD
5 AMP
RIGHT REAR
RETRACT
HOLD
EXTEND
CONTROL PANEL
A B
ELECTRICAL
CONNECTION
DIAGRAM
HYDRAULIC
MANIFOLD
CONNECTION A
CONNECTION B
CONNECTION B
REPLACEMENT VALVE WILL NOT
HAVE MANUAL SHUT OFF.
KEEP MANUAL SHUT OFF IN THE OPEN POSITION.
(PARELLEL WITH MANUAL VALVE BODY AS SHOWN.)

REPAIR STEPS
SOLUTION DIAGRAMS
PROBLEM
MI91.2167
16APR98
Part 11
After turning the
master switch
"ON" and push-
ing the Automat-
ic Switch to "RE-
TRACT":
a. The red "RETRACT"
light does not blink.
Check voltage and connections. Check the bulb. If the system works
manually and levels automatically, the problem is the control panel.
b. The pump does
not run when the
master switch is
turned "ON" but
starts to run when
the Automatic Switch
is pushed to "RE-
TRACT".
Replace the control panel.
c. One or more jacks
will not retract or
the red warning lights
do not go out.
Recheck the system in the manual mode. Any problem occuring at
this time can be found by operating the system manually.
d. The control panel
will not shut off. Replace the control panel.
Part 10 continued
REFER TO MP65.3455
h. Jacks do not ex-
tend to stabilize the
vehicle. The pump
runs under no load.
The adjustable relief valve is not working properly and should be re-
placed.
i. Jacks extend to
stabilize the vehicle,
but lift the vehicle
too high or do not
extend to the ground
fully.
The relief valve needs to be adjusted. Loosen the jam nut. If the ve-
hicle is lifting too high, turn the adjusting bolt counterclockwise. If the
vehicle needs more pressure on the jacks to stabilize, turn the adjust-
ing bolt clockwise.
Turn the adjusting bolt 1/2 turn at a time and retry the system. Repeat
until the proper adjustment is reached. If adjustments do not help, re-
place the relief valve. REFER TO MP65.3455
j. The pump does
not shut off.
Turn the master switch off. If the pump stops turn the master switch
back on. If the pump starts to run see Part 3d of the Repair Steps. If
the pump does not run the control panel may be the problem. Retry
the automatic leveling function. If it works ok, the problem was a stuck
relay. Check voltage and all connections.
FRONT
RIGHT REAR
RIGHT
ADJUSTABLE
RELIEF VALVE
RELIEF VALVE
ADJUSTABLE
FRONT
RIGHT REAR
RIGHT

MP65.3455
03FEB98
+ + + +
RIGHT
REAR
RIGHT
FRONT
LEFT
LEFT FRONT
REAR
RIGHT
FRONT
LEFT
FRONT
LEFT
REAR RIGHT
REAR
ACTUATOR
STAB. H/V
HYDRAULIC LINE CONNECTION DIAGRAM
400 SERIES LEVELING SYSTEM
WITH KICK-DOWN JACKS
NOTE: SOME SYSTEMS HAVE
A 1 PORT DRAIN VALVE. ONLY
THE ACTUATORS ARE CON-
NECTED TO THE DRAIN.
NOTE: DRAIN VALVES
ARE OPTIONAL
3 PORT
DRAIN VALVE
SHUTTLE
VALVE
RETURN
LINE
ADJUSTABLE
RELIEF VALVE
CHECK
VALVES (4)
PUMP
PRESSURE
LINE
BREATHER
CAP
(OIL FILL)
FRONT
REAR
NOTE: THE BLEED VALVE IS LOCATED INSIDE
THE MANIFOLD BEHIND THE SHUTTLE VALVE.
REMOVE THE SHUTTLE VALVE AND ADJUSTABLE
RELIEF VALVE TO ACCESS THE BLEED VALVE.
CHECK PUMP
PRESSURE OF
THIS FITTING

MP65.3458
03FEB98
+ +
RIGHT
REAR
RIGHT
FRONT
LEFTLEFT FRONTREAR
NOTE: DRAIN VALVES
ARE OPTIONAL
STAB
HYDRAULIC LINE CONNECTION DIAGRAM
400 SERIES LEVELING SYSTEM
WITH STRAIGHT-ACTING JACKS
LF RF
LR RR
SHUTTLE
VALVE
CHECK
VALVES (4) ADJUSTABLE
RELIEF VALVE
RETURN
LINE
BREATHER
CAP
(OIL FILL)
FRONT
REAR
4 PORT
DRAIN VALVE
CHECK PUMP
PRESSURE AT
THIS FITTING