RV Generator Runs But No Power (Do This Now!)

Have you ever wondered why your RV generator runs but not producing any power? Look no more.

We`ve got you covered.

When you are away from the beaten tracks with your RV, the primary source of electricity will most likely be the generator you have installed in it.

It will provide power for all of your appliances in your motorhome or camper trailer, on which depends whether your trip in the wilderness will be enjoyable or ruined.

Not many things are unpleasant as slowly steaming in your RV while your perishables are going bad because your AC and fridge are not working due to lack of power.

The role of the generator is to provide you with electricity by using the internal combustion engine combined with a generator. But sometimes it can happen that it is running and not producing any power.

So, why your RV generator runs but not producing any power? If your RV generator is running but not generating power, you need to check the following steps, including:

– Step #1: Check generator’s breakers

– Step #2: Check output leads

– Step #3: Check again circuit breakers

– Step #4: Check voltage at terminal blocks

– Step #5: Check the main fuse box of the RV

– Step #6: Check the generator transfer switch

– Step #7: Find an appliance that is shorting

– Step #8: your generator was overloaded

So, keep on reading to find out when and why this can happen, and how to fix it.

Table of Contents

Why Generator Can Run Without Power In RV?

The role of an electrical generator in an RV is to use chemical energy in the fuel to produce mechanical energy which is then in turn transformed in the alternating current.

The chemical energy is transformed into mechanical energy the same way as in your car or RV when cruising down the roads, with an internal combustion engine.

There are two reasons why a generator can keep on running while no AC power is reaching your appliances.

The most common one is some type of break in the electric lines, and usually is not a reason for great concern.

The second reason is a faulty alternator on the engine of your generator.

Both of these issues make no impact on the generator engine’s ability to run properly and safely, and thus it doesn’t shut down.

Generator Running but No Power to RV >> Check out the video below:

How To Fix Lack Of Power

The generator is the main source of electrical power needed for all of the appliances you can have in the RV when there is n shore power outlet to hook it up to.

If your appliances lose power, they will not be able to provide you with their benefits.

This can be a very alarming situation if you are not experienced with the repair of generators.

But, there are several causes that can lead to this situation, and none of them is an indication of a faulty generator.

And you can rest assured that the generator itself is working properly.

So, let’s move on to finding and fixing the cause of this type of behavior of your RV generator.

Troubleshooting The Problem

As I have said above, in general, there are two reasons why a generator may keep running but your RV still not receiving the 120 volts alternating current electricity.

It can be either a faulty alternator or a break in the power lines after the generator.

Because, in essence, in both of these situations everything is OK with your generator, it will continue working.

But, it still remains to precisely diagnose and fix the problem.

So let us move on with the actual troubleshooting of the problems by starting with the one which is very often the easiest one to diagnose.

Faulty alternator

In case that the alternator has failed, most generators will enter a so-called engine running only or ERO mode.

Some generators have a very simple and elegant system for notifying a user of any fault during the work.

Some have an indicator light that continuously lights when everything is properly working.

In case that there is some fault, it will start blinking a repeating sequence that signifies the fault code of the problem.

“In case that there is a problem with the alternator and it switches to ERO mode, this indicator light will start rapidly blinking on and off.”

The most common problem with an alternator is blown diode, which can be very easily be diagnosed and repaired by virtually any car shop.

So, if you see the indicator light blinking rapidly, your best course of action is to shut down the generator and take it to a shop.

Other makes and models of generators have a different way of signaling the problem with the alternator, so the best you can do is to consult the user/operator manual to see how exactly it is reported.

In case that everything is OK with the alternator, some generators will have the indicator light on continuously.

Some other types will have a different way to signal that everything is working the way it should, and you should consult the manual for your model for the exact way it will do it.

Electric Lines Break

If you don’t have much experience with electricity, this can sound alarming.

But most of the time it means that the circuit breaker was tripped somewhere, which is its function anyway, to break the circuit under certain conditions.

It doesn’t necessarily mean that you have faulty wiring, so let’s get on with troubleshooting them first, as they are the most likely cause.

Step #:1 Check generator’s breakers

Before you start doing anything you must turn off the generator by pressing the STOP button, or whatever is the correct stopping procedure according to your user manual.

Once it is stopped, you should remove the access panel and find where are two breakers that protect the generator from overloading and short circuits.

On some models, these two are usually on the side of the plastic housing of the controls.

If any of these two was tripped, you should reset it and turn the generator back on.

If nothing happens, something led to the temporarily overloading of your generator, and you should try to remember whether you have turned on some device just before you have lost the power.

But, if right, as you start it the breaker, gets tripped again, you have a short circuit and should move to Step #7 to diagnose which device is to blame.

Step #2: Check output leads

If neither of these two breakers was tripped, you should check the output leads of the generator, chances are that some have come off due to vibrations.

If everything is tight and secure, move to Step #3.

Step #3: Check again circuit breakers

In case that circuit breakers are not tripped, they might be faulty.

So, you should check them for continuity at both terminals with a multimeter.

In case that there is no continuity on one of them, it means that it is faulty and you will need to replace it according to the manual for your particular model of generator.

Step #4: Check voltage at terminal blocks

This step is not to be performed if you don’t have experience with testing the voltage of live wires with a multimeter.

120V of alternating current can be deadly if you don’t treat them with respect.

If you have never done it before, you should leave it for a professional, and skip to Step #5 and eliminating other possible causes.

Now that you are warned about the dangers, and if you are skilled enough and know how to treat live wires, here’s what you need to do.

Generators usually have two or three terminal blocks, and you will have to check the service manual for your generator how they are wired.

You will need to check the voltage with the multimeter across them while the generator is running.

If there is around 120V they are OK, otherwise, if any of them reads considerably lower voltage, the wiring needs to be checked whether it is securely connected and if it is so, to be replaced.

If the voltage is around 120V you will need to replace the AC harness, but if there is no voltage, you will need to replace the control assembly because it’s faulty.

Both of these are best left for professional technicians, so taking the RV to a dealership is the best course of action.

If everything is OK, but you still have no power, move to the next step.

Step #5: Check the main fuse box of the RV

In case that everything is OK with breakers and wirings on the generator itself, there are chances that there is a problem in the RV’s systems.

So the next thing you should check whether some breaker was tripped in the main fuse box of the RV, in case that some of them are tripped you should move them back to ON position, and start the generator again.

In case that the same breaker gets tripped again as soon as you restart the generator, it means that some of the appliances are shorting and you should move to Step #7.

In case that everything works fine, you should try to remember whether you had powered some device just before your RV lost power, if so, it was the thing that overloaded the generator and you should try to decrease the number of devices you have turned on.

Step #6: Check the generator transfer switch

Most of the RVs have an automatic generator transfer switch that automatically starts drawing power from the generator when it is started.

If you have easily accessible shore power, you should plug it in to check whether the generator transfer switch is malfunctioning.

In such a case, you will have power in the RV when connected to shore power, but not when connected only to the generator.

In this situation, you will have to take the RV to a shop for the replacement of the transfer switch.

In case that your RV is an older model, it may not have a transfer switch, but the generator needs to be manually hooked up to RV’s system.

“Where precisely it is located you can find in your RV’s manual, but generally, it is a small hatch on the side of the RV, around three feet from the generator’s hatch.”

In case that connecting the RV to shore power trips a breaker, you are dealing with an appliance that is shorting and should move to the next step.

Step #7: Find an appliance that is shorting

When some appliance is shorting it will trip either the generator’s breakers or the RV’s breakers.

And it will do it every time you switch the power back on after resetting the tripped breaker.

Finding that faulty appliance is a very straightforward process, though it can be a bit boring.

You need to unhook all appliances from power outlets, start the generator, and then reconnect the one at the time.

Make sure that at any time you have only a single appliance plugged in.

The faulty appliance will trip the breaker as soon as you plug it in.

Step #8: your generator was overloaded

In case that plugging in and turning on appliances one at a time doesn’t trip the breaker, you should start plugging them one by one, instead of one at a time.

Eventually, after plugging in and powering on one of the appliances, the breaker will trip because you have put too high of a load on your generator.

This can happen for two reasons, either your RV has too small a generator or you are at too high an altitude for the generator to produce its maximum output.

Many generators, especially propane-powered ones, are sensitive to altitudes above 5,000 feet, and their maximum power output can drop by as much as 15%.

Onan RV Generator Runs But No Electricity – Watch this fix

Onan RV Generator runs but no electric power – watch this fix >> Check out the video below:

References

https://www.flightsystems.com/pdf/onan-rv-troubleshooting-guide.pdf

https://www.manualslib.com/manual/1898306/Cummins-Onan-Hdkah.html?page=76#manual