RVMP Flex Power 4000i User manual

Read this manual carefully before operation.
This manual includes important guidance for safety operation.
Authorized for installation ONLY in Recreational Vehicles prepped by the RV Manufacturer with fuel lines and a compartment
for permanent generator installs. Do NOT install in any other application without consulting a qualified professional.
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RVMP FLEX POWER
4000i &5500i
INSTALLED GENERATORS
SERVICE MANUAL
®®
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Introduction 2
Safety Precautions 2
Troubleshoot Issue #1:Generator tries to start, some lights illuminate on the control panel, but generator will not start. 4
Check battery 4
Check oil level 4
Check spark plug circuit for adequate spark 5
Check spark plug for damage 7
Check proper function of fuel module, ECM, and inverter on 4000i 8
Electrical Harnesses 8
Fuel module 8
Engine Control Module (ECM) 8
Inverter 8
No reaction from throttle motor 8
No 120V output 8
Inverter cooling fan does not spin 9
Green READY light never comes on 9
Check proper function of fuel module, starter, and inverter on 5500i 9
Electrical Harnesses 9
Fuel module 9
Starter 9
Inverter 10
Pull start test 10
No reaction from throttle motor 10
No 120V output 10
Inverter cooling fan does not spin 10
Green READY light never comes on 10
Check for restrictions to gasoline line 10
Check for vacuum lock in the gasoline line 11
Check housing temperature sensor disc 11
Check gasoline solenoid on carburetor 12
Check alternate fuel source 12
Check fuel pump 13
Check fuel selection switch 13
Troubleshoot Issue #2:Generator starts sometimes, but will not start other times (intermittent starting). 13
Check battery 13
Check oil level 13
Check electrical grounds 14

Battery ground cable connection 14
Ground posts 14
Grounding jumper wire for mounting rack 16
Troubleshoot Issue #3:Generator completely dead, does not attempt to start and no lights illuminate on control panel. 17
Check battery 17
Check fuses 18
Small fuel module fuse 18
Larger inverter fuse for 4000i 18
Larger inverter fuse for 5500i 18
Troubleshoot Issue #4: Generator starts but runs rough when the breaker is OFF with no electrical load on the generator.
18
Check throttle for proper operation 18
Inspect wire harnesses 18
Check for a bad stepper motor 18
Check for bad inverter 19
Check needle jet for dirt or obstructions 20
Check proper setting on altitude adjustment 22
Clean old gas or buildup from carburetor 23
Drain old gasoline 23
Run with LP 23
Clean carb with Sea Foam 23
Air filter inspection and cleaning 23
Check for gasoline vaporization conditions 24
Check for proper LP regulator pressure 24
Check for low LP 24
Troubleshoot Issue #5: Generator starts but only runs for a few minutes, then shuts down. 24
Check for proper ventilation 24
Check for gasoline vaporization conditions 26
Check for proper LP regulator pressure 26
Check for restrictions to gasoline line 26
Check for vacuum lock in the gasoline line 27
Troubleshoot Issue #6: Generator starts and runs but there’s no power output. 27
Check for electrical overload 27
Check for bad inverter 27
Instructions for replacing fuel pump 28
Instructions for replacing the fuel filter 33
Instructions for replacing the carburetor 35
1

RVMP®Flex Power®Generators
Troubleshoot and Service Manual
Introduction
This is the troubleshoot and service manual for FLEX POWER generator models 4000i and 5500i. While these models share
many similarities, note several sections of this manual where the technical differences between the models are explained in
detail.
Safety Precautions
Read and understand all instructions before installing or operating on this product. Adhere to all safety labels. This manual
provides general instructions. Many variables can change the circumstances of the instructions, i.e., the degree of difficulty,
existing equipment, operation and ability of the individual performing the instructions. Failure to correctly follow the provided
instructions may result in death, serious personal injury, severe product and/or property damage and may void portions of
the warranty (See Owner’s Manual for warranty info). We recommend that installation and servicing is performed by a
qualified and experienced RV technician.
This manual cannot provide instructions for every possible scenario, but provides the general instructions, as necessary, for
troubleshooting and servicing the generator in most situations. If you have any questions, please contact us at:
RV Mobile Power, LLC
Phone: (855) HAPPYRV
Email: [e-mail]
www.rvmp.co
FIRE SAFETY NOTICE
Keep multi-class ABC fire extinguishers handy. Class A fires involve ordinary combustible materials such as wood and cloth.
Class B fires involve combustible and flammable liquid fuels and gaseous fuels. Class C fires involve live electrical equipment.
WARNING
The "WARNING" symbol above is a sign that a procedure has a safety risk involved and may cause death or serious personal
injury if not performed safely and within the parameters set forth in this manual.
●Failure to follow instructions provided in this manual may result in death, serious personal injury
and/or severe product and property damage, including voiding all or portions of the warranty.
2

●Do not operate equipment when mentally or physically fatigued or after consuming alcohol or
drugs.
●Do not use starting fluids which can cause an explosion and may result in death, serious personal
injury and/or severe product and property damage. Do not use evaporative starting fluids. They
are highly explosive.
●Installing or maintaining a generator can cause severe personal injury. Wear personal protective
equipment including safety glasses, hard hats, steel-toed shoes and protective clothing when
working on equipment.
●Benzene, found in some fuels, and used engine oils have been identified by some state and
federal authorities to cause cancer or reproductive toxicity. Do not ingest, breathe fumes or come
into contact with gas or oil when checking, draining or adding gas and oil.
●Hot, moving and electrically-live parts can result in death, serious personal injury and/or severe
product and property damage. Only trained and experienced personnel should make adjustments
while the generator is running. Otherwise, adjustments should be made only when the generator is
not running.
●Moving parts can catch on loose clothing items or jewelry. Do not wear loose clothing or jewelry
near moving parts including shafts, fans, belts and pulleys.
●Moving parts can seriously injure body appendages, including fingers. Keep hands away from
moving parts. Keep protective guards in place over fans, belts, pulleys and other moving parts.
●Improperly installed electrical connections may result in death, serious personal injury and/ or
severe product and property damage. Electrical connections must be made by trained and
experienced electricians in accordance with applicable codes.
●Back-feeding to shore power may result in death, serious personal injury and/or severe product
and property damage. The generator must not be connected to shorepower or any other source of
electrical power. An approved switching device must be used to prevent interconnections and
serious damage to the generator.
●Operating, servicing and maintaining and maintaining this equipment can expose you to
chemicals, including engine exhaust, carbon monoxide, phthalates and lead, which are known to
the State of California to cause cancer and birth defects or other reproductive harm. To minimize
exposure, avoid breathing exhaust, do not idle the engine except as necessary, service your
equipment in a well-ventilated area and wear gloves or wash your hands.
●Do not install the generator on a watercraft or boat. Such an installation might violate U.S. Coast
Guard regulations and may lead to damage, fire, injury, or death.
3

CAUTION
The "CAUTION" symbol above is a sign that a procedure has a safety risk involved and may cause personal injury, product or
property damage if not performed safely and within parameters set forth in this manual.
●Always wear eye protection when performing service, maintenance or installation procedures.
Other safety equipment to consider would be hearing protection, gloves and possibly a full face
shield, depending on the nature of the task.
Troubleshoot Issue #1:Generator tries to start, some lights illuminate on the
control panel, but generator will not start.
Check battery
Check the battery for at least 12-13V DC. Use a multimeter to determine the battery voltage by applying the
probes to the positive and negative terminals on either the battery itself or the terminals on the side of the generator
which accept the positive and negative battery cables.
Check the battery for at least 450 CCA. For lead acid batteries, use a battery tester to measure the cold
cranking amps (CCA) of the battery and ensure at least 450 CCA. For lithium batteries, ensure that the battery has a
state of charge (SOC) of at least 25%.
Check oil level
The generator is equipped with an oil level sensor that prevents the generator from starting when the oil level is
too low. There is a Low Oil light on the front control panel that will illuminate when the sensor measures an oil level that
is below the threshold for starting. Generally speaking, the generator oil capacity must be almost completely filled in
order for this switch to actuate and allow the generator to start. The sensor for the oil level is very sensitive and so even
having slightly too little oil will prevent the generator from starting.
If the Low Oil light is illuminating, this indicates that the low oil float is sending spark energy to the light.
If the Low Oil light is not illuminating, it is possible the spark circuit is not producing adequate power. Check
the spark circuit for adequate power.
If the Low Oil light is illuminated but the generator is full of oil, there could be an issue with the float switch in
the oil sensor. Try unplugging the oil sensor and see if the generator starts. You can unplug the wire harness for the oil
sensor in order to temporarily disconnect this sensor, but make certain that the generator is full of oil before trying this
and NEVER operate the generator without having the oil sensor plugged in and operating, this is only for a quick test. If
the generator starts, then there is likely a problem with the float in the sensor and it may need replaced. If it doesn’t
start, proceed to check the other problems.
If the oil reservoir is full but you know there is not enough oil in the unit, there is likely an air bubble inside the
oil pan and/or crank case. To remove the bubble, pull the manual start or try to start the unit from the start button (it
may take several pulls or attempts to start in order to completely remove the air).
4

Check spark plug circuit for adequate spark
Remove spark plug boot and unscrew spark plug from the engine with a spark plug socket. Re-attach the spark
plug boot and carefully observe the spark plug gap while trying to start the generator. Be sure to stay clear of the spark
plug gap and only observe for a spark with the naked eye. Depending on the amount of ambient light, the spark may not
be observable and this does not necessarily mean there is a bad spark plug.
If a spark cannot be observed with the naked eye, use an inline spark tester to determine if there is adequate
spark from the spark circuit. Place the in-line tester in between the boot and the spark plug and attempt to start the
generator. When using an inline tester it should be easy to determine the amount of light being generated by the tester
and this indicates the strength of the spark circuit burst.
If the inline spark tester indicates only a small amount of light when attempting to start the generator,
re-check the voltage on the battery and make sure that it’s not too low. Also check the ignition coil for proper
resistance as described above.
If the inline spark tester indicates a proper amount of light when attempting to start the generator, then
the spark plug circuit for the generator is working properly.
If there is no light observed within the inline spark tester, then there is a problem with the spark circuit,
likely the ignition coil.
To check an ignition coil for proper function, check the following two resistances with a digital multimeter
placed on the resistance setting (Ω):
1. Main ignition coil harness. Place one multimeter probe on the first conductor inside the
harness and the other multimeter probe on the second conductor and measure this resistance.
This measurement should be around 1-2 ohms. If the resistance is infinite, there is an open
circuit failure and the ignition coil needs to be replaced.
5

6

2. Output spark plug wire. Place one multimeter probe on the first conductor inside the harness
and the other multimeter probe on the interior conductor of the spark plug boot. This
measurement should be around 15,000 ohms. If the resistance is infinite, there is an open
circuit failure and the ignition coil needs to be replaced.
Check spark plug for damage
If the generator is new, it’s very unlikely that the spark plug would be bad and therefore prevent the generator
from starting. However, in some situations even a new spark plug could be fouled by too much fuel during the initial
startup, perhaps by holding the Prime button down for too long before attempting to start the generator. If this
happens you should smell fuel, but perhaps not in all cases. To overcome this situation, simply allow the fuel to dry off
the spark plug and then attempt to restart after about ten minutes.
If the generator has been used previously, it’s possible that the spark plug has gone bad, especially if the
generator was used in less than ideal conditions. For example, if the air filter is clogged the balance of fuel to air in the
carburetor will not be in balance and fuel deposits will be left on the spark plug.
●Normal Wear: The electrode and insulator should have a tan or light brown color, indicating the plug is
functioning well.
●Fouling: Look for deposits like oil, fuel, or carbon buildup on the electrode. Fouling can hinder the spark plug's
performance.
●Wear and Tear: Examine for any cracks, chips, or other visible damage.
●Serious Corrosion: Examine the threads of the spark plug and the electrode for corrosion.
Replace the spark plug if there are noticeable signs of fouling, wear and tear, or corrosion.
Proper spark plug gap: 0.024 in - 0.0315 in (0.60 mm - 0.80 mm)
7

Check proper function of fuel module, ECM, and inverter on 4000i
Electrical Harnesses
The 4000i requires electrical communication between the various components such as the fuel module, ECM,
and the inverter in order to start and run properly. In some instances, it's possible that one of the electrical harnesses
came unplugged through vibration or snagging when the cover was attached/replaced. If the generator is not starting
or running properly be sure to check all wire harnesses.
Fuel module
During normal operations, when the start button is pressed there should be audible indications from the fuel
pump or fuel solenoid of proper starting operations. When the fuel selection switch is on gas, you should hear the fuel
pump running as part of the startup sequence. When the fuel selection switch is on LP, you should hear the gas
solenoid module click. If you hear nothing when the start button is pressed, check the 10 Amp fuse to the fuel module
(located near the front control panel) as this may be blown and if so this is preventing the fuel module from getting
power and operating the fuel pump/fuel solenoid properly.
Engine Control Module (ECM)
The 4000i model does not use a traditional starter, but instead uses the windings inside the stator/rotor of the
generator to create a spark. When pressing the start button, If you can hear the fuel pump running or the fuel solenoid
‘click’ but there is no spin or attempt to spin the rotor in the generator then it’s possible that the ECM could be bad. To
test for this, try using the manual pull start to start the generator. If the generator starts with the pull start but will not
start with the start button, then the ECM is likely bad. Replace the ECM to confirm.
Inverter
Generally speaking, if the inverter had a failure the unit should still be able to start and run (although rough).
So if a 4000i generator is failing to start it's not likely due to a bad inverter.
No reaction from throttle motor
However, if there is NO reaction from the throttle motor once the generator starts, it is possible that the
inverter could be bad because during proper operation the inverter supplies the throttle motor with instructions on
when to increase/decrease the throttle due to electrical load(s) on the generator. Thus, during proper operations, the
throttle motor should be making adjustments during idle and also once an electrical load is applied. If the inverter fails
to send proper instructions to the throttle motor, the RPM of the motor would stay constant regardless of whether there
is any type of electrical load on the generator or not. If this scenario is present, try swapping out the throttle motor for a
motor that is known to be working. If the throttle motor still does not move with a working replacement, then it's likely
that the inverter is bad and needs replaced.
No 120V output
Additionally, there could be a failure in the inverter if the generator starts but there is no 120V output. You can
observe this failure by looking at the digital display on the front of the unit once the generator starts and pressing the
option button on the display until the output voltage is displayed. If zero volts is indicated on the display for the output
8

power then it's likely the inverter is bad. This can also be checked by placing a multimeter on the two 120V AC output
wires and see if there is proper voltage output. If not, the inverter is likely bad.
Inverter cooling fan does not spin
Additionally, there could be a failure in the inverter if the fan on the side of the inverter does not spin once the
generator starts. This fan gets 120V power from the inverter so if this fan is not spinning, there is likely a failure in the
inverter.
Green READY light never comes on
Additionally, there could be a failure in the inverter if the generator starts but the green READY light will not
come on. In this situation the OVERLOAD light will remain on but the green READY never illuminates and this is likely
the sign of a failure in the inverter.
Check proper function of fuel module, starter, and inverter on 5500i
Electrical Harnesses
The 5500i requires electrical communication between the various components such as the fuel module, starter,
and the inverter in order to start and run properly. In some instances, it's possible that one of the electrical harnesses
came unplugged through vibration or snagging when the cover was attached/replaced. If the generator is not starting
or running properly be sure to check all wire harnesses.
Fuel module
During normal operations, when the start button is pressed there should be audible indications from the fuel
pump or fuel solenoid of proper starting operations. When the fuel selection switch is on gas, you should hear the fuel
pump running as part of the startup sequence. When the fuel selection switch is on LP, you should hear the gas
solenoid module click. If you hear nothing when the start button is pressed, check the 10 Amp fuse to the fuel module
(located near the front control panel) as this may be blown and if so this is preventing the fuel module from getting
power and operating the fuel pump/fuel solenoid properly.
Starter
The 5500i uses a starter to generate the electrical energy for the spark. If the generator is not starting with the
START button, try using the manual pull cord start. If the generator starts with the pull cord but not with the START
button, then the starter could have a failure.
Check for a failure in the starter by performing a resistance winding test using the digital multimeter placed on
the resistance setting (Ω). Place the positive probe of the meter on the positive supply and negative probe of the meter
on the housing and read the resistance measured by the multimeter. The resistance should be zero or very very low.
The resistance should not be infinity (completely open). If this resistance is over 0.1 ohms then there is likely a direct
short in the starter and it needs to be replaced.
9

Inverter
Pull start test
The 5500i uses the inverter to control the start sequence, so if the generator will not start it could be a
bad inverter. To test for this, attempt to start the generator using the manual pull cord and listen for the fuel
pump or the fuel solenoid ‘click.’ If the fuel pump does not run (when on gasoline) and the solenoid does not
click (when on LP) then it's possible the inverter is bad.
No reaction from throttle motor
If there is NO reaction from the throttle motor once the generator starts, it is possible that the inverter
could be bad because during proper operation the inverter supplies the throttle motor with instructions on when
to increase/decrease the throttle due to electrical load(s) on the generator. Thus, during proper operations,
the throttle motor should be making adjustments during idle and also once an electrical load is applied. If the
inverter fails to send proper instructions to the throttle motor, the RPM of the motor would stay constant
regardless of whether there is any type of electrical load on the generator or not. If this scenario is present, try
swapping out the throttle motor for a motor that is known to be working. If the throttle motor still does not move
with a working replacement, then it's likely that the inverter is bad and needs replaced.
No 120V output
Additionally, there could be a failure in the inverter if the generator starts but there is no 120V output.
You can observe this failure by looking at the digital display on the front of the unit once the generator starts
and pressing the option button on the display until the output voltage is displayed. If zero volts is indicated on
the display for the output power then it's likely the inverter is bad. This can also be checked by placing a
multimeter on the two 120V AC output wires and see if there is proper voltage output. If not, the inverter is
likely bad.
Inverter cooling fan does not spin
Additionally, there could be a failure in the inverter if the fan on the side of the inverter does not spin
once the generator starts. This fan gets 120V power from the inverter so if this fan is not spinning, there is
likely a failure in the inverter.
Green READY light never comes on
Additionally, there could be a failure in the inverter if the generator starts but the green READY light will
not come on. In this situation the OVERLOAD light will remain on but the green READY never illuminates and
this is likely the sign of a failure in the inverter.
Check for restrictions to gasoline line
If the generator will not start, check the gasoline lines from the tank to the generator to ensure that there are no
kinks or bends. Also check to make sure that a clip or zip tie has not closed off the flow of gasoline through the fuel line
or constricted it in any way. If the fuel line is being restricted you should hear the fuel pump begin to get louder once
there is no fuel or a small amount of fuel within the pump. If you hold down on the prime button and the fuel pump gets
10

louder and/or makes a ‘clicking’ sound, there is either no fuel or a small amount of fuel getting into the fuel pump, and
therefore some type of restriction in the gasoline line.
Check for vacuum lock in the gasoline line
If the generator will not start, check the gasoline lines for possible vapor lock. When drawing gasoline from a
tank that contains a separate fuel pump for the RV chassis engine or a fueling station, this can create a vapor lock in the
gasoline line that will prevent the fuel pump of the generator from overcoming the vacuum and drawing fuel into the
generator. If this occurs, you should hear the fuel pump begin to get louder once there is no fuel or a small amount of
fuel within the pump. If you hold down on the prime button and the fuel pump gets louder and/or makes a ‘clicking’
sound, there is either no fuel or a small amount of fuel getting into the fuel pump, and there could be a vapor lock
preventing fuel from getting to the generator.
In these situations, the gas cap on the gasoline tank can be loosened to allow the vacuum to release. However,
DO NOT leave the gas cap loosened as gas may be able to spill out of the tank when the RV is moving. If you are
consistently experiencing vapor lock, explore a vented gas cap for the tank that will allow air into the tank and remove
the vacuum.
Check housing temperature sensor disc
If the generator will not start, check the temperature disc at the top of the generator for a possible failure or not
being plugged in. After removing the housing there is a bundle of wire harnesses at the center of the generator and the
top of this bundle contains a housing shaped like a disc that contains a thermocouple for measuring the temperature
within the housing.
11

In some instances, this temperature sensor can fail, especially when exposed to very high ambient
temperatures for a long period of time. Try unplugging the wire harness for the temperature sensor and see if the
generator will start. If so, there is a failure in this temperature sensor and it needs to be replaced. DO NOT operate the
generator without this temperature sensor or there will be no thermal protection for the generator if temperatures rise
above the operational parameters and into a high temp damaging scenario which could damage various components of
the generator permanently.
Check gasoline solenoid on carburetor
If the generator will not start on gasoline, it is possible that the fuel solenoid on the carburetor is stuck and will
not open to allow fuel into the carburetor. Try starting the generator on LP and if it starts with LP then there could be an
issue with some restriction in the fuel line, vapor lock, or the solenoid on the carb could be stuck. Check for proper fuel
at the carburetor by loosening the screw at the carburetor bowl and holding down the prime button. Fuel should be
coming out of the bowl. If not, there could be some restriction in the fuel line, vapor lock, or the solenoid on the carb
could be stuck.
To test for a stuck solenoid on the carb, hold down the prime button and listen for two important items: 1) fuel
pump running and 2) a ‘click’ from the carburetor when the solenoid opens. If you do not hear the ‘click’ then it's
possible that the solenoid is stuck and not opening. This can be caused from sitting for long periods of time, especially
in a highly corrosive environment, where a buildup of corrosion prevents the solenoid from operating properly. To fix
this, hold down the prime button while tapping lightly on the carb with a screwdriver to free the solenoid.
Check alternate fuel source
If the generator will not start on one fuel source, it can often be helpful to try the alternate fuel source in order
to rule out any issues with the ignition coil, ECM, or other electrical components involved in the starting process. For
example, if the generator will not start on gasoline, try switching the fuel selector switch over to LP and connecting an
LP tank (if not already connected) and starting the generator on LP. If the generator starts on LP but will not start on
gasoline, we know that there is no issue with the spark plug, ignition coil, ECM, or other common starting components
12

and that the issue must be within the specific gasoline supply components like the fuel pump, fuel tank, or fuel supply
lines. Similarly, if the generator starts with gasoline but will not start with LP, then we know the issue likely has to do
with the specific LP supply components like the regulator, gas solenoid, or LP supply.
Check fuel pump
If the generator will not start on gasoline, check to ensure that gasoline is reaching the carburetor. This can be
done by loosening the screw on the carburetor bowl and holding down the PRIME button on the control panel. When
functioning properly there should be fuel coming out of the bowl. If not, listen to see if you can hear the fuel pump
running when you hold down on the PRIME button. If you do not hear the fuel pump running, there could be a failure in
the fuel pump and this may need to be replaced. Also if you do not hear the fuel pump running when you hold down the
PRIME button, ensure that the fuel selection switch is on gasoline, as the fuel pump will not run when the fuel selection
switch is positioned on LP.
Check fuel selection switch
If the generator will not start on gasoline, check to ensure that the fuel selection switch is all the way UP to
select gasoline. Ensure that the switch is all the way up. You can hear a ‘click’ when the switch moves back and forth
from LP to gasoline. Similarly, if the generator will not start on LP, check to check to ensure that the fuel selection
switch is all the way DOWN to select LP. Ensure that the switch is all the way down.
Troubleshoot Issue #2:Generator starts sometimes, but will not start other
times (intermittent starting).
Check battery
Check the battery for at least 12-13V DC. Use a multimeter to determine the battery voltage by applying the
probes to the positive and negative terminals on either the battery itself or the terminals on the side of the generator
which accept the positive and negative battery cables.
Check the battery for at least 450 CCA. For lead acid batteries, use a battery tester to measure the cold
cranking amps (CCA) of the battery and ensure at least 450 CCA. For lithium batteries, ensure that the battery has a
state of charge (SOC) of at least 25%.
Check oil level
The generator is equipped with an oil level sensor that prevents the generator from starting when the oil level is
too low. There is a Low Oil light on the front control panel that will illuminate when the sensor measures an oil level that
is below the threshold for starting. Generally speaking, the generator oil capacity must be almost completely filled in
order for this switch to actuate and allow the generator to start. The sensor for the oil level is very sensitive and so even
having slightly too little oil will prevent the generator from starting.
Due to the sensitive nature of the oil level sensor, when the RV is parked on uneven ground the oil in the pan can
shift causing a low oil error which prevents the generator from starting. This can cause intermittent starting because
the generator will run fine when on level ground but will not start when the RV is on an incline. To remedy this situation,
simply add some oil to the generator to ensure the dipstick is showing full even when the RV is parked on an incline.
13

Similarly, if you are operating the generator while the RV is moving it is possible then when the RV goes
up/down an incline or stops quickly, the oil in the pan can shift causing a low oil error which will stop the generator (if
running) or prevent the generator from starting. To remedy this situation, simply add some oil to the generator to
ensure the dipstick is showing full even when the RV is traveling up/down an incline or stopping suddenly.
Check electrical grounds
It is possible that a loose electrical ground or bad electrical ground can allow the generator to start in some
situations but will not start in others.
Battery ground cable connection
For the negative battery cable connection, it is recommended to run a single battery cable from the
battery ground connection post on the left side of the generator directly to the negative terminal on the battery.
This ensures a proper path back to the battery. However, in some applications the negative battery cable can
simply be grounded to the steel on the chassis of the vehicle. If the latter approach is used, ensure that the
negative battery cable has a good connection with the chassis. Conduct a visual inspection to ensure there is
no rust or coatings that prevent proper electrical contact between the cable and the steel chassis. Wiggle the
connection to see if it’s loose and if so tighten or re-attach with a better connection. A multimeter can also be
used to check the continuity at the connection point on the chassis with other known grounds.
Ground posts
The generator has two ground posts that can become loose and cause intermittent starting. The first
post is on the exterior left hand side of the generator and is the location where the negative battery cable
attaches to the generator. The second post is on the interior of the generator in the front right corner beneath
the fuel selection switch where several internal ground wires are connected. Each of these locations are
indicated in the figures below.
14

15

To mechanically check each post, conduct a ‘wiggle’ test by grasping one of the wires connected to the
post or the post itself and attempt to wiggle the post. If either post is loose, tighten accordingly.
To electrically check each post, use a digital multimeter placed on the resistance setting (Ω) to look for
continuity:
A) between a known ground on the chassis or battery and the first exterior post. Place one probe on
the known ground and the second probe on the first exterior post where the negative battery
cable connects. The resistance should be zero.
B) between a known ground on the chassis or battery and the second interior post. Place one probe on
the known ground and the second probe on the second interior post underneath the fuel
selection switch. The resistance should be zero.
C) between the two posts. Place one probe on the first exterior post where the negative battery cable
connects and the second probe on the second interior post underneath the fuel selection
switch. The resistance should be zero.
If either A, B, or C produce a measurable resistance value with the digital multimeter, then there is a
ground that does not have a good electrical connection with the ground posts and battery
ground wire. Check each ground wire to ensure that it's electrically connected properly and
that no wires have been cut and/or damaged in any way that would prevent proper electrical
connection.
Grounding jumper wire for mounting rack
When using the mounting rack with the generator, it can be difficult to access the first exterior post for
the negative battery cable once the generator is placed within the mounting rack. Thus, a grounding jumper
wire is sometimes used to connect the first exterior post for the negative battery cable with another post that is
connected and grounded with the mounting rack itself. See the figure below for illustration. The design allows
16

for a faster installation when using the mounting rack, but care must be used to ensure the jumper wire is used
and correctly installed.
As shown above, a proper grounding jumper wire would connect its first end to the first exterior post on
the generator and its second end to the negative battery cable post on the mounting rack. It’s imperative that
there is a grounding washer placed between the second end of the jumper wire and the mounting rack to ensure
that proper electrical connection is made between the two. The mounting rack is constructed of hardened steel
which is then powder coated, so that proper electrical connection with the jumper wire may not occur unless a
grounding washer is used, which will cut into the mounting rack slightly to ensure good metal to metal contact
for the grounding wire.
●If a jumper wire is not used be sure that this is included (the generator may still start/run
intermittently without a proper jumper wire).
●Ensure that a proper grounding washer is used or the mounting rack is sufficiently sanded
and/or prepped to ensure good electrical connectivity.
●Also ensure that the wire’s connections are not loose by conducting a ‘wiggle’ test.
Troubleshoot Issue #3:Generator completely dead, does not attempt to start
and no lights illuminate on control panel.
Check battery
Check the battery for at least 12-13V DC. Use a multimeter to determine the battery voltage by applying the
probes to the positive and negative terminals on either the battery itself or the terminals on the side of the generator
which accept the positive and negative battery cables.
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Check the battery for at least 450 CCA. For lead acid batteries, use a battery tester to measure the cold
cranking amps (CCA) of the battery and ensure at least 450 CCA. For lithium batteries, ensure that the battery has a
state of charge (SOC) of at least 25%.
Check fuses
A pair of in-line electrical fuses are placed adjacent to the front control panel and protect various aspects of the
generator from damage. If a fuse is blown, then the generator will be completely dead and would have no response
when the start button is pushed.
Small fuel module fuse
A single ten (10) amp fuse is used to protect the fuel module. This fuse can be blown if there is a short
in the fuel pump or the fuel solenoid on the carburetor. Check this fuse and replace if necessary. If blown, be
sure to check the fuel pump and fuel solenoid for proper operation before resuming operations of the generator,
or else the new fuse will be blown as well.
Larger inverter fuse for 4000i
A single sixty (60) amp fuse is used to protect the inverter on the 4000i model. This fuse can be blown
if the battery is connected backwards. Check this fuse and replace if necessary. If blown, be sure to check the
battery connections before resuming operations of the generator, or else the new fuse will be blown as well.
Larger inverter fuse for 5500i
A single one-hundred (100) amp fuse is used to protect the inverter on the 5500i model. This fuse can
be blown if the battery is connected backwards. Check this fuse and replace if necessary. If blown, be sure to
check the battery connections before resuming operations of the generator, or else the new fuse will be blown
as well.
Troubleshoot Issue #4: Generator starts but runs rough when the breaker is OFF
with no electrical load on the generator.
Check throttle for proper operation
Even without an electrical load on the generator, there should be some movement of the throttle, although
slight. After starting the generator, closely watch the throttle and throttle spring to see if there is any movement
whatsoever. If there is no movement, there are several scenarios to check for. The throttle is located at the top of the
carburetor, which is placed adjacent to the right side of the front control panel. Images below provide the location of
the carburetor and a close up of the throttle and spring. When observing the proper function of the throttle, watch the
black plastic throttle that is connected to the spring and there should be some movement of this throttle/spring for
proper operations. If there is no movement, proceed to check the following.
Inspect wire harnesses
Check the wire harness for the throttle stepper motor and ensure that the wire harness is fully plugged
in and engaged.
Check for a bad stepper motor
The stepper motor which controls the throttle is a digital stepper motor so it can be difficult to verify a
failure in the motor aside from swapping out the questionable motor with a known working stepper motor. The
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