Norac UC4 Total Control User manual

UC4™Total Control™
Quick Guide
2007
Canada
NORAC Systems International Inc.
CALL TOLL FREE: 1-800-667-3921
[phone]
SHIPPING ADDRESS:
3702 Kinnear Place
Saskatoon, SK
S7P 0A6
United States
NORAC, Inc.
CALL TOLL FREE: 1-866-306-6722
[phone]
SHIPPING ADDRESS:
6667 West Old Shakopee Rd., Suite 111
Bloomington, MN
55438
For other service locations please view our website:
www.norac.ca
Improving the Competitiveness of Industry and Agriculture
through Precision Measurement

Printed in Canada
Copyright 2006 NORAC Systems International Inc.
Reorder P/N: 446BC-MAN5-2 Revision A
NOTICE
NORAC Systems International Inc. reserves the right to improve products
and their specifications without notice and without the requirement to update
products sold previously. Every effort has been made to ensure the accuracy
of the information contained in this manual. The technical information in this
manual was reviewed at the time of approval for publication.

TABLE OF CONTENTS
1 INTRODUCTION....................................................................................................1
2 OPERATOR SAFETY............................................................................................2
3 BASIC UC4 OPERATION .....................................................................................3
3.1 NORMAL OPERATING SCREEN...............................................................3
3.2 CHANGING TO AUTOMATIC OR MANUAL MODE....................................4
3.3 ADJUSTING THE TARGET HEIGHT (SETPOINT) .......................................5
3.4 VIEWING THE ACTUAL BOOM HEIGHT ..................................................5
3.5 CHANGE THE SYSTEM SENSITIVITY (SENSI) ........................................6
3.6 CHANGING BETWEEN SOIL AND CROP MODE......................................6
3.7 PERFORMING A RETUNE........................................................................7
4 COMMON SYMPTOMS AND SOLUTIONS ......................................................8
4.1 GENERAL OPERATION ...........................................................................8
4.2 SENSOR RELATED ISSUES....................................................................10
4.3 HYDRAULIC RELATED ISSUES .............................................................14
4.4 BOOM INSTABILITY AND MAIN LIFT....................................................18
4.5 ACTIVE AND PASSIVE ROLL ................................................................19
5 UC4 ERROR MESSAGES.................................................................................... 21
5.1 SYSTEM SETUP ERROR MESSAGES ......................................................21
5.2 OPERATIONAL ERROR MESSAGES .......................................................23
6 SENSOR AND ROD ALIGNMENT.................................................................... 25
6.1 WING SENSORS....................................................................................25
6.2 PASSIVE ROLL SYSTEMS......................................................................26
6.3 ACTIVE ROLL SYSTEMS.......................................................................28
7 QUICK REFERENCE .......................................................................................... 30
8 STATEMENT OF LIMITED WARRANTY.......................................................33

1
1 INTRODUCTION
This booklet is a quick on-site reference for the operator of the UC4
automatic boom height control system.
This booklet is intended to be used in conjunction with the:
UC4 Total Control Automatic Boom Height Technical Manual
(UC4 Technical Manual)
UC4 Total Control Automatic Boom Height System Installation
Manual (UC4 Installation Manual)
It is important for the operator to be familiar with the UC4 Technical
Manual before attempting operation. As well, it is assumed that the
operator is familiar with navigating through the UC4 control panel menu
structure and with making setting adjustments.
Section 3 outlines basic operation of the UC4 control system.
Section 4 describes solutions for common symptoms regarding the UC4
system operation. Irregular behavior is sometimes a combination of several
causes. Please take time to read this section thoroughly.
Section 5 presents common error messages on the UC4 control panel’s
LCD screen.
Section 6 discusses detailed information regarding the sensor and rod
alignment. This information will be useful to operate and maintain the
system efficiently.
Section 7 is a quick reference to the common symptoms. It guides you to
find a proper solution quickly when experiencing difficulty during System
Setup or field operation.
This guide is based on UC4 software Version 5
If you can not determine the cause of your problem, contact your dealer or
NORAC for assistance.
Phone: [phone] Canada (Toll Free)
1-866-306-6722 United States (Toll Free)
(+33) (0)4 26 47 04 42 Europe
1-306-664-6711 all other regions
E-mail: [e-mail]
Web Site: www.norac.ca

2
2 OPERATOR SAFETY
DANGER
STEP 1: Always ensure that the UC4 system is powered
down or in MANUAL mode:
before leaving the operator’s seat
while the machine is not moving
or when transporting the machine
STEP 2: Under no circumstances should any service work
be performed on the machinery while the UC4 system is
in the AUTOMATIC mode.
STEP 3: Before working on any part of the booms:
set the UC4 system to MANUAL mode
turn the sprayer engine off
STEP 4: Do not operate this system before:
reading and understanding the UC4 Technical
Manual
thoroughly understanding your machine operation
STEP 5: The UC4 system will greatly improve your
spraying height accuracy and protect the boom against
damage in a wide variety of field conditions. However,
under some circumstances performance may be limited.
The OPERATOR of the sprayer must remain ALERT at
all times and override the automatic control when
necessary. Refer to the warranty statement in Section 0
for more details.

3
3 BASIC UC4 OPERATION
Upon power-up a sequence of messages are temporarily displayed on
the control panel LCD screen
- the system is ready for use once the Normal Operating Screen
(Figure 1) is displayed
To access either the SENSOR DISPLAY or SETUP menus ensure
you are at the Normal Operating Screen
- toggle toward the menu you wish to access
- adjust the menu settings using the " +/- " switch while the prompt
is displayed
After 30 seconds menu prompts will return to the Normal Operating
Screen
To return to the Normal Operating Screen toggle and hold the "SETUP
(NO)" switch for two seconds
New settings take effect once the Normal Operating Screen is displayed
Figure 1 – SENSOR DISPLAY / SETUP Switch and Normal Operationg
Screen
3.1 NORMAL OPERATING SCREEN
In AUTOMATIC mode the digits represent target boom height in
inches
In MANUAL mode the digits represent actual boom height in inches
DISPLAY
SENSOR
SET UP MANUAL
+
DISPLAY
SENSOR AUTO
UC4
BO OM
CO NTROL CONTROL
+
SETUP
SETUP
SENSOR
DISPLAY
MANUAL
AUTO
BOOM
UC4
(NO)
(YES)
(NO)
(YES)

4
Table 1 – Examples of Normal Operating Screens
3.2 CHANGING TO AUTOMATIC OR MANUAL MODE
From the Normal Operating Screen toggle the control panel "AUTO"
switch to change between MANUAL and AUTO modes
In MANUAL mode, the boom may be controlled as usual with the
boom control switches on the sprayer’s multifunction handgrip
Operating the sprayer’s left or right boom control switches while in
AUTO mode immediately causes that boom to revert to MANUAL
mode.
- the sprayer’s joystick switches override automatic height control
on either the left, right, or both sides
To return to AUTO mode the "AUTO (YES)" switch must be
activated.
The target height (Section 3.3) can be adjusted by momentarily
pressing the sprayer’s main lift control switches (main up or main
down).
Pressing and holding the sprayer’s main up or down switches for more

5
36 34 36
36 AA 36
than two seconds reverts ALL booms (left, right, main and roll) to
MANUAL mode.
- this is a convenient method for switching to MANUAL mode
when folding for transport
3.3 ADJUSTING THE TARGET HEIGHT (SETPOINT)
The system is in AUTO and can have the
target height adjusted
Use the " +/- " switch in AUTO mode to adjust the target height
setting.
Alternately, adjust the main boom target height by momentarily
pressing the sprayer’s main lift control switch while in AUTO mode
- each press of the up/down switch increases/decreases the target
height by one inch, respectively
The smallest target height setting is called the minimum height
override.
Default minimum height settings are factory programmed before
shipping.
3.4 VIEWING THE ACTUAL BOOM HEIGHT
Left boom is at 36”, right center section is
at 34” and right boom is at 36”
Toggle the "SENSOR DISPLAY" switch to view actual boom heights.
- the left, main (center) and right boom heights are displayed on this
screen
To view additional sensor heights (if installed) toggle the "SENSOR
DISPLAY" switch again.
To lock the currently viewed sensor heights on the screen indefinitely
toggle the " +" switch once
Height menus can be viewed in both AUTO and MANUAL mode.
More information on sensor height menus is available in the UC4
Technical Manual.

6
Sensi 5
Crop on
Soil on
3.5 CHANGING THE SYSTEM SENSITIVITY (SENSI)
A sensitivity setting of 5 (default setting)
Toggle the "SETUP” switch to view the current Sensi setting
- while viewing this menu, toggle the " +/- " switch to adjust the
Sensi value.
- lower numbers reduce system sensitivity and improve stability
- increasing the number will speed up the response (five is the
default setting)
If the Sensi setting is modified, the panel will return to the Normal
Operating screen after 3 seconds.
A lower Sensi setting may be required for stable control at the start
of operation (before sprayer is warmed up).
As the sprayer warms up increase the Sensi setting until the
performance reaches an optimum level.
Refer to the UC4 Technical Manual for a discussion of performance
issues
3.6 CHANGING BETWEEN SOIL AND CROP MODE
System is in CROP mode
System is in SOIL mode
SOIL or CROP mode can be adjusted in both MANUAL and AUTO
modes.
To view the current setting, toggle the "SETUP (NO)" switch twice.
While viewing this menu, use the " +/- " switch to change between
SOIL and CROP mode.
- wait five seconds for the change to take effect on all sensors
If the mode is modified the panel will return to the Normal Operating
screen after 3 seconds.

7
3.7 PERFORMING A RETUNE
NOTE: Sensors are not adjusted or calibrated by
performing a ReTune. A retune recalibrates the hydraulic valve
parameters.
Perform a system return when:
When a hydraulic solenoid valve is changed.
When the hydraulic pump is changed or adjusted.
When the normal working temperature of the hydraulic oil has shifted
significantly from when the system was previously calibrated.
If you are running a pull type sprayer and use different tractors to
operate the sprayer, you should perform a ReTune each time the
tractor is changed.
If you have a flow control for the boom hydraulics, set it prior to
tuning. If you change the flow setting by more than 20 percent, you
should perform a ReTune.
Before starting a ReTune:
Prepare the equipment and select an appropriate location (refer to the
UC4 Technical Manual for more details)
Performing a ReTune:
Navigate to the "ReTune?" menu prompt in the SETUP menu.
To start a ReTune, confirm with the "AUTO (YES)" switch.
Follow the instructions on the LCD screen.
NOTE: If an error occurs during a ReTune, refer to Section 4 and 5.
If the solution is not listed, contact NORAC. During the
ReTune, progress will be displayed on the LCD screen. Please
record these displayed messages before or while the error
occurs. Providing us with these messages will help determine
the problem.

8
4 COMMON SYMPTOMS AND SOLUTIONS
This section discusses common symptoms and suggested solutions
when the UC4 control system is being installed or operated.
It is recommended that you use Section 7 to identify your problem and
use that reference to navigate to the details within this section.
4.1 GENERAL OPERATION
4.1.1
LCD screen does not light up
System resets itself when a boom valve is turned on
Possible Cause(s) Suggested Solution(s)
a) Inadequate power
supply
NOTE:
If your system is operating below
+12 volts, this may cause a
problem. If you have a low
voltage problem, it could be due
to the sprayer’s electrical system
(e.g. faulty alternator, battery, or
poor ground connection).
a-1) Ensure the UC4 power cable is connected
to the UC4 control panel
a-2) Ensure the UC4 power cable is connected
to the sprayer’s power supply properly.
a-3) Ensure the sprayer’s power supply
voltage is high enough (more than +12V).
Measure the supply voltage when the
valve is being used, since the valve action
may cause a voltage drop.
b) Defective power cable b) Follow a-1) to a-3). Wiggle cables/wires
around. If the symptom continues, the
cable may need repairing.
c) Damaged LCD screen
c) Follow a) and b). If the symptom
continues, the screen may need replacing.
4.1.2
Part of the LCD screen is black
Some of the digits do not appear on the LCD screen
LCD screen turns black (high contrast) temporarily
Possible Cause(s) Suggested Solution(s)
The control panel is
mounted so that direct
sunlight hits the front panel
(LCD screen)
High temperature causes the LCD screen to
turn black (high contrast). This symptom will
disappear when the LCD cools down.

9
4.1.3
UC4 randomly switches between AUTO and MANUAL modes
LCD screen display changes erratically
UC4 system unintentionally goes into MANUAL mode
Possible Cause(s) Suggested Solution(s)
a) Poor cable connection
NOTE:
Connectors used to interface
with sprayer hydraulics are often
located outside and are
susceptible to moisture.
a-1) Ensure that all cables are correctly
connected according to the UC4
Installation Manual. The connections
should be tight and free of corrosion.
a-2) Wiggle cables/wires around while in
AUTO mode. This will detect any
interruptions, as it will change the system
into MANUAL mode.
b) Defective cable(s) b) Follow a-1) and a-2). If the symptom
continues, the cable may need repairing.
c) Electrical noise on the
sprayer’s D.C. system c) Add a power line filter or freewheeling diodes on one or more of the sprayer’s
solenoid valves.
4.1.4
Height increases/decreases unintentionally
Possible Cause(s) Suggested Solution(s)
Intermittent electrical
noise on the main lift
interface cable(s).
NOTE:
This is similar to when the
operator momentarily presses
main up/down buttons to
increase/decrease the spray
height setpoint (Section 3.3).
a) Try installing a power line filter
b) Diodes may have to be installed in the
main lift lines (these must be sized
appropriately for the sprayer ex. IN5408
for a 3 Amp or smaller coil)
Contact NORAC for more information
4.1.5
UC4 system does not go into AUTO mode
Possible Cause(s) Suggested Solution(s)
a) Incomplete System
Setup (Install) Perform an Install successfully (see Section 4.1 of the UC4 Technical Manual)
b) Accidentally initiated
an Install and aborted
it before completion

10
4.1.6
Boom does not appear to be sufficiently level after System Setup
Possible Cause(s) Suggested Solution(s)
a) Sensitivity (Sensi)
setting is low a-1) Check the nozzle heights on LCD screen in
MANUAL mode
a-2) If the displayed heights differ from the
target heights (setpoints), check Sensi
setting and adjust it, if necessary.
NOTE: The default tolerate distance between the
actual nozzle heights and the target heights is
±2.5" at Sensi setting of 5.
b) Improper System
Setup b-1)Repeat the Automatic System Setup (Section 8.2 of the UC4 Technical Manual)
b-2)Confirm sensor height readings manually
by referring to “Calibrating the Sensor’s
Height Reading (Zero Height)” in the UC4
Technical Manual.
4.2 SENSOR RELATED ISSUES
4.2.1
Display stuck at “"Mot’n Dly" or "KP Stp 9"
Possible Cause(s) Suggested Solution(s)
a) Sensor is too close to
the boom a) Move the sensor to a better location. It should be 9” of front of and 9” above the
spray nozzle. The sensor requires a 12”
diameter clear view of the ground
b) The target is too weak b) Move to a new location with either dirt or
gravel on the ground
c) Make sure there is no grass or other plants
under the sprayer boom
d) Verify the sensor is approximately parallel
to the ground

11
4.2.2
Sensor appears not to work: Displaying "NC"
Wrong number of sensors displayed during System Setup
Displaying "Absent" during System Setup – Sensor Detect
Possible Cause(s) Suggested Solution(s)
a) Serial number (SN)
entered in the control
panel does not match
the connected
sensor’s SN
a) Check SNs entered in the control panel and
verify numbers with each sensor in the
respective boom location. Reenter the
correct SN, if necessary.
b) Poor cable connection
or defective cable(s) b) Follow a), 4.1.3a-1) and perform Sensor Swapping described in 4.2.6. If the
symptom continues, the cable(s) may need
repairing.
c) Ensure the sensor cables are not strained or
pinched by boom fold actions
c) Damaged sensor d) Follow b). If the symptom appears in the
moved boom location, the sensor may need
repairing.
4.2.3
Invalid sensor measurement: Displaying "NR"
Possible Cause(s) Suggested Solution(s)
a) Sensor is out of range
or reading a target
closer than 7"
a-1) Move the boom(s) until sensor(s) is
between 30 and 60 inches above the
ground.
a-2) Check sensor alignment (Section 6).
NOTE: If the sensor is facing forward/backward too
far, the signal cannot echo back to the sensor.
a-3) Check for obstructions between the sensor
and the ground.
NOTE: Any object between them can deflect the signal
such that it cannot echo back to the sensor.
b) Protective foam shield
is contaminated b) Inspect and clean the foam shield. Remove the foam and clean with compressed air.
NOTE: Do not blow out the foam while it is still in the
sensor. Sensor damage will result.

12
4.2.2 continues
c) Protective Weather
Caps are not removed.
* Prior to 2004 shipped
sensors only
c) Remove the Protective Weather Caps that
fit over the mouth of the sensor.
d-1)Moisture in sensor
d-2)Direct exposure to
rain
NOTE:
It may cause this error
especially if the sensor mouth
points upward while sprayer
booms are folded to transport
position. Measures should be
taken to minimize rain
exposure to sensors.
d-1)Remove the protective foam shield and
check the sensor’s transducer foil.
d-2)Allow the transducer to dry.
NOTE: The foil is the gold-colored material beneath
the metal screen. The foil should be clean, dry
and wrinkle free.
NOTE: Running the sensor will accelerate the drying
effect.
e) Ultrasonic transducer
is damaged or
contaminated
e) Follow a) to d-1), and listen to the sensor
for a ticking sound. If the sensor is not
ticking or the transducer is contaminated,
the sensor may need repairing.
4.2.4
Sensor not working: Displaying "##" or "-#" (too high or low)
Possible Cause(s) Suggested Solution(s)
a) Boom section is too
high ("##"). a) Lower the boom section
NOTE: The sensor is reporting a reading that has too
many digits to display on the LCD screen.
When the boom returns to normal heights, the
reading should reappear on the screen.
b) Sensor Zero Height
setting is incorrect b) Check the sensor Zero Height. Calibrate it, if necessary.
NOTE: Refer to Section 8.5.3.1.2 Calibrating the
Sensor’s Height Reading in the UC4 Technical
Manual.
NOTE: This symptom may occur when sensors have
been “swapped” from different mounting
locations.
c) Sensor is facing very
strong sonic targets
(e.g. concrete)
NOTE:
This may cause measurement
errors, flashing from a valid
height reading to "0","##" or
"-#"
c) Try a different/adequate target.

13
4.2.5
Displaying "SNR xxxx" during Automatic System
Possible Cause(s) Suggested Solution(s)
a) Improper sensor
alignment
NOTE:
Sensor is not reading the
ground or the target properly
a) Check sensor alignment (Section 6),
primarily the sensor involved with the
error. For example, if the System Setup is
performing a "LftDet" and this message
appears, check the Left wing sensor(s).
b) Poor targets such as
wet gravel or stubble b) Try a different target.
4.2.6 Sensor Swapping
Swapping Sensors is a useful procedure for determining whether a sensor
error message (e.g. "LO NR") is due to the sensor or the wiring to the
sensor.
NOTE: A sensor may have power and emit a ticking sound, but have broken
communication wire(s), which would cause this error. Performing Sensor
Swapping would help determining the cause.
The procedure is as follows:
i) Exchange the affected sensor with one that is reporting correctly
(e.g. "LO" and "RO").
ii) Swap (input) their respective location serial numbers into the control
panel (Refer to Section 8.5.3.1.1 “Entering Sensor Serial
Numbers” in the UC4 Technical Manual).
iii) If the problem still exists in the same location ("LO NR"), and the
sensor on the "RO" is reporting correctly, the wiring from the left
outer ("LO") branch may have a fault and the sensor itself is
functional.
iv) If the error appears on the right outer sensor ("RO NR"), the sensor
may not be functioning.

14
4.3 HYDRAULIC RELATED ISSUES
Determine whether the problem is hydraulic or electrical
If your hydraulic valve has an override pin, use it to manually open the
valve
If there is no reaction the problem is hydraulic, if the boom moves the
problem may be electrical
NOTE: If there is a bypass valve with the hydraulic system, the bypass valve is also
needed to open at same time as with the tested valve.
Hydraulic
4.3.1
Boom(s) will not raise or lower
Possible Cause(s) Suggested Solution(s)
a) Hydraulic oil is not
being supplied to the
NORAC valve block
a) Ensure that oil is being supplied to the
NORAC valve block in the proper
direction (Tank and Pressure lines).
NOTE: If the direction is wrong, the check valve may
prevent oil from flowing through the valve.
b) Hydraulic quick
couplers are not
properly connected
b) Ensure that all quick couplers in the
hydraulic system are properly connected.
c) Not enough back-
pressure to activate
the check valves in
the NORAC valve
block
NOTE: Some Single Acting
valve systems only
c) Place orifices in the “A” lines going to
Tank (“T”) in order to create sufficient
back-pressure to activate the pilot-operated
check valves in the NORAC valve block.
4.3.2
Booms will not lower
Possible Cause(s) Suggested Solution(s)
Insufficient back-pressure
to activate the pilot-
operated check valves in
the NORAC valve block
Some single acting circuits may require orifices
be placed in the “A” lines going to the tank

15
4.3.3
"Timeout!" error during System Setup
Possible Cause(s) Suggested Solution(s)
a) Hydraulic cylinder
has reached the end of
its stroke but the
system is still trying
to move in that
direction
a-1) Ensure the hydraulic cylinders are not
being prevented from moving by a cylinder
cap.
a-2) If a cylinder is fully extended or retracted,
manually reposition the boom into the
middle of the cylinder stroke and resume
the setup with the "AUTO (YES)" switch.
a-3) For left and right booms that do not adjust
below the level of the main boom, ensure
that the main boom is within 50 inches
above ground before attempting an Install
or ReTune (System Setup).
b) Boom is moving too
slow b) Ensure the hydraulic oil is at working temperature.
c) Not enough pressure
to the hydraulic
circuits at main lift
("MlfDet") Boom
Geometry Tuning
NOTE: This is for sprayers
with load-sensing hydraulic
circuits.
c-1) Ensure the solution pump is running.
c-2) Put the hydraulic system into high pressure
manually.
NOTE: On a John Deere sprayer, this can be
accomplished by pressing and holding the
brake.
d) The sensor may be
reading off the boom d-1)Move the sensor to a location where the boom will not interfere with the sensor
readings
4.3.4
Boom raises when it should lower, or vice versa
Possible Cause(s) Suggested Solution(s)
a) Wrong valve cable
connection a) Ensure cable connection to the NORAC valve block
b) Wrong plumbing b) Ensure the plumbing is correct:
The boom raise line(s) connect(s) to the “B” port(s)
on the NORAC valve block.
The boom lower line(s) connect(s) to the “A” port(s)
on the NORAC valve block.
The Tank and Pressure lines connect to the Tank
(“T”) port and Pressure (“P”) port on the NORAC
valve block, respectively.

16
4.3.5
Boom(s) creep up or down in MANUAL mode
Boom will not stay level or settle over a long period of time
Possible Cause(s) Suggested Solution(s)
a) Internal problem with
the NORAC valve
block (e.g. a sticking
or worn valve)
a) The valve block may need repairing or
replacing.
b) Cylinder leakage b) The cylinder sealsmay need replacing.
c) Faulty check valve(s)
in the NORAC valve
block
c) The check valve(s) may need replacing.
d) Foreign object stuck
in an internal port of
the NORAC valve
d) If possible, remove the foreign object or
the valve block may need repairing.
e) Not enough back-
pressure to activate
the check valves in
the NORAC valve
block
NOTE: Some Single Acting
valve systems only
e) Follow 4.3.1c).
f) Problem within the
sprayer’s hydraulic
network (system)
f) Check the sprayer’s hydraulic network.
4.3.6
Boom(s) creep(s) upwards when in the transport position
Possible Cause(s) Suggested Solution(s)
a) Valve leakage a) The valve block may need repairing or
replacing.
b) Faulty check valve(s)
in the NORAC valve
block
b) The check valve(s) may need replacing.

17
4.3.7
Hydraulic oil overheat
Sprayer shuts down or alarm sounds due to the hydraulic oil overheat
Possible Cause(s) Suggested Solution(s)
a) High performance
automatic boom
leveling system
requiring elevated
amounts of hydraulic
power to constantly
maintain proper
setpoint is increasing
oil temperature
a) Lowering the Sensitivity ("Sensi")
setting may reduce the system activity and
lower the temperature as a result.
b) Plumbing single
acting systems as
double acting with
both A ports orificed
may reduce heating
b) Contact NORAC for more information
c) Depending on your type of system, other adjustments may be made.
Electrical
4.3.8
Boom(s) will not raise or lower
Possible Cause(s) Suggested Solution(s)
a) Poor cable
connection, defective
cable(s) or defect in
the NORAC valve
block
a-1) Check all cable connections between the
control panel and the valve block. Ensure
that they are tight and free of corrosion.
a-2) Check the LCD screen in which the valve
command arrows ("" or "") appear.
a-3) Measure the voltage at the valve
connection.
a-4) If there is no voltage, the cable(s) may
need repairing or replacing.
a-5) If there is sufficient voltage (+12V), and
the valve is not reacting, the valve may
need repairing or replacing