THE GENERATOR SEEMS DEAD - THE GENERATOR RUNS BUT THERE IS NO POWER IN MY ROADTREK!

This article applies to Roadtreks with the Onan gasoline powered generator Microlite 2800 models up to the KY model that came out mid to late 2012. It applies to the KV model that is the model before the KY and should apply to earlier Onan's.  I DO NOT KNOW if it applies to the newest Onan Microlite 2800 model as that has a very different motor.

 

The Onan Microlite 2800 gasoline  generator in the Roadtrek will at times not start - it does not try to start and stop. When the start switch is pressed - either on the wall or inside the generator itself - the motor seems to be DEAD! This could be a mechanical issue inside the Onan but the first thing to check is the FUSE inside the Onan.  Early Roadtreks had the Onan in a compartment on the outside of the van on the side wall.  These are easy to work with inside the generator. Later Roadtrek moved the generator under the chassis of the van.  Look under the rear bumper toward the driver's side and you will see it hanging down.  The FUSE is inside the generator case. The fuse is between the Roadtrek battery(ies) and the ignition of the generator motor and this goes through the generator's control panel. 

 

 

Sometimes the generator starts just fine - and runs perfectly but there is no 120 volts of AC power coming out of the generator.  You turn on the A/C and nothing happens! You turn on the microwave and nothing happens! The first thing to check is the CIRCUIT BREAKER inside the Onan! The internal Onan CIRCUIT BREAKER is between the Onan's output and the Roadtrek! 

As you can see in the illustration above - the breaker and the fuse are near each other. 

 Getting to the Onan when it is under the chassis -  

I should not have to say this but before going to the generator SHUT THE GENERATOR OFF!

 Sorry to say, you have to crawl under the back of the van's rear bumper on the driver's side either on your back or on your belly. When you get close enough it will be above your head - and it is a pain to work on it propping yourself up on your elbows or reaching up on your back looking at it upside down. 

You then have to remove the access panel on the front of the Onan's case by pushing up on the two buttons - shown in the first illustration - at the same time and then pull forward and down on the panel to take it off.  Once the panel is off you will see an  open space in the middle - as shown in the second illustration.  In the picture here it is easy to see. Looking inside the Onan upside down or trying to look up at it - it is not so easy to see.  You might not see it all all.  if that is the case you are going to have to rely on touch.  

 FOR THE FUSE - PUT TWO FINGERS IN AND FEEL FOR IT - it is a regular automotive blade type fuse - 5 amps. Get hold of it with two fingers and pull it out (try not to drop it). Look into the center of the top of the fuse and see if the metal connection inside is broken. If so the fuse is blown and must be replaced - and when you do so the generator will start right up - if this was what the problem is. 

FOR THE CIRCUIT BREAKER -  PUT A FINGER DOWN AND FEEL FOR THE LITTLE BLACK HANDLE THAT POINTS TO THE PASSENGER SIDE.  Once you find it push it DOWN TO RESET IT and then with a finger under it PULL IT UP TO SET IT. It will click into place and stay there.    

 If you want to wait to put the access panel door back on and go and try the generator to see if all is well, then there is no problem leaving it off until you go inside and turn on the generator and if it was the fuse make sure it starts and if it was the circuit breaker to make sure you now have power.  Then crawl under again and put the access panel back on.    You have to push up the two buttons again and put the top in first and swing the bottom into the Onan to close the panel - once set in let go of the buttons  and if they don't want to go on their own - push them down to lock the panel on. 

IF you changed the fuse and want to start the generator with the internal start switch - shown above - you can BUT the generator when it starts is going to vibrate and you do not want to have your hands or your head anywhere close to it. I don't recommend it having done it. 

 WHY DID THE FUSE BLOW?  The generator may have overloaded when starting.  When the generator is being difficult to start - do not just keep holding onto the start switch inside the Roadtrek. Let off the switch - wait a half minute and then push the button again. After several attempts to start it - let is sit for ten minutes and then try again.   

 WHY DID THE CIRCUIT BREAKER TRIP? This can happen if a load over 2800 watts is put on the Onan - A/C turned on and then the Microwave is turned on at the same time. AC is running and a hair dryer is plugged into an RT outlet and turned on.   

BUT IT IS VERY COMMON FOR THE BREAKER TO BE SHUT OFF WHEN ANYONE - PRO OR OWNER DOES ANYTHING INSIDE THE ONAN - INCLUDING JUST CHECKING THE OIL.                                                    

What happens is the set breaker handle is located close enough to the top of the open space that hands easily hit it down and turn it off. I have been at an Onan shop and when they told me it was ready and aI went inside to turn it on and make sure - and the Onan is running - great! - BUT the microwave display is dark (this is a quick place to look to see that you have power as when plugged in or running the Onan the display is lit - even though the microwave is not turned on. I turned on the A/C just to make sure - A/C - it did not start - just like it was dead - which it is without any 110/120 volt electricity. I called the service tech back over and told him to go under again and put the breaker back on - as he obviously hit it when he was working inside. He was not happy. They hate going under to work on it also. 

WHAT IF NEITHER OF THESE WORK TO FIX IT?    

The least expensive thing to have happened is a connection from either the fuse or the breaker came off of the Control Board. This happened to me - found by an Onan service tech - we both thought it was the breaker but a wire from the breaker came loose on the control board inside the Onan.  Worst case is there is something much bigger wrong with the Onan.                                                                                                                                                                                                                                                                ======================  

The last time I had my Onan in for service I watched the service tech go under in a different way to work on the Onan. He rolled under on a mechanic's creeper from behind the driver's rear tire from the driver's side of the Roadtrek. He was not on the ground. The mechanic's creeper lifted him up high enough to more easily look inside and get inside of the Onan. Every so often Harbor Freight stores put a nice creeper on sale for less than $30. (No I don't work for Harbor Freight and I get nothing from them for mentioning their store! (I wish I did 😉!) 

The two illustrations are from the Onan KV manual.  If you do not have an Onan manual, EMAIL US! and I have a KV and a KY manual that I will email you the one you need. I also have a KV service manual which is very thick in pages. I can email that to you if  you ask for it - it is for the KV but the basics will apply to the KY. Be sure to tell me in the email if your Onan is a KV or KY so that you get the correct manual.  These are no longer easy to find on the Cummins/Onan website.                                                                                                                                                                                                                                                     

                                                                                                                                                                                                      

THE ONAN GENERATOR

 My 2011 Chevy based Roadtrek 190 Popular has the Onan Microlite 2800 KV model generator. Since this model, starting in 2012, Onan introduced a changed generator model  -  the Microlite 2800 KY generator. Since that model there have been two other model Onan Microlite 2800 generators. The most current - that was never used in a Chevy based Roadtrek - is the Onan QG 2800i. It was not used as it did not exist when RT stopped building Chevy based Roadtreks. It can be installed in a Chevy Roadtrek to replace an older model or as a new install.  I am not familiar at all with the Onan that came between the KY and the OG2800i.  All are gasoline powered generators. The only Roadtreks that have a propane generator - installed by Roadtrek - are the diesel engine Roadtreks - none of which are on a Chevy chassis.

In earlier Roadtreks the generator was installed in a cabinet on the outside of the Roadtrek with easy access.  Later, Roadtrek mounted the generator under the chassis of the Roadtrek in the rear driver's side of the van. This location is very difficult to access and requires crawling under the van with very low clearance, reaching up on your arms to open an access panel to the inside of the case, and then craning your neck up to try to see inside the generator to check the oil, change the oil, and reset a circuit breaker and replace a fuse - both of which will be covered later in this article. I have watched Onan service technicians get under the van to work on the Onan much easier by rolling under on a mechanic's creeper. This raises them up enough to better reach in and see inside a little better and not be too high to fit under. They roll in from the side behind the driver's side rear tire.

The position of the generator is rather precarious for the low ground clearance van.  A pot hole and bottoming out can hit the generator. A flooded street can submerge the generator. A steep inclined (or declined) driveway can bottom out the rear of the van and hit the generator. Of course, none of these things are good for the generator. Always be aware of the road and what you are going over when driving a Chevy based Roadtrek with the generator on the bottom. 

The differences between the Onan Microlite 2800 KV and KY models are these. The KV model has an owner accessed altitude adjustment for the motor. The owner can do this easily on their own - following the instructions in the KY manual. The KY model has an owner non-accessible altitude adjustment that -  per Onan - requires a technician to adjust and the addition of a part.  The KY model has a troubleshooting lamp system. The power light on the KY's wall switch flashes a code sequence if there is a problem with the generator. The code sequences are defined in the KY manual. There is NO troubleshooting lamp in the KV model Onan.  The KY also has a priming button to prime the generator before starting. To do this the bottom of the start button is pushed in once or twice to prime the motor with gasoline. The KV model does NOT have ANY priming function. Pushing in of the start button of the KY model only shuts the motor off if it is running.

 The new OG generator model is stated to be much quieter than previous Onan generators. It has a different motor than previous Onan models that is not supposed to require the same exercise schedule of the previous generator which was once a month for two hours of continuous runtime under half a load (the A/C in summer or a plugged in electric space heater in cold weather. The installation of the OG model using the same mounting holes under the chassis that the KY, KV used, requires an adapter plate sold by Onan to make the new case holes match up with the previous drilled  holes under the chassis.

The basics of starting the Onan are covered in our article THE GENERATOR found here. The Onan KV manual may be downloaded here.   For the KY manual, I am not finding a current link any longer for this manual. If you would like a copy of the PDF file of the KY manual that I have, please contact me using the Email Us link in the right column of this page. 

 There are maintenance items that are listed in the manual that are not to be ignored. They include changing the fuel filter, changing the oil (minimum once every year or per hour schedule in manual), changing the air filter, and changing the spark plug. On RV shop that I took my Roadtrek to for the fuel filter change would not do the job without taking the generator down off the bottom of the van. I did not have them do the job. I then took it to an authorized Onan service center that changed the fuel filter with the generator still attached under the van.  If any shop tells you that there is an oil filter - there is NO oil filter.  Some authorized Onan shops will do all of these items when they do an oil change. Can you change the oil yourself - yes. The grade oil to use depends on the area you drive the Roadtrek in the most - and there is a chart in the manual that specifies which oil for which type of environment. Changing the oil means doing this on the ground with you on your back reaching up - or on your elbows if you are on your stomach. Checking the oil means removing the oil cap which has a small dip stick on it. Take out the dipstick and wipe it off. Put it back in BUT leave it on the top - do not screw it back down. The oil is checked with the stick on the top of the oil fill rim.  To drain the oil there is a drain plug under the Onan. There is a specific torque that MUST be used when screwing this plug back in. Only use a torque wrench when doing this set to the correct torque which is in the manual.  I had a shop that did not do this and they stripped threads on the pan. The pan had to be replaced. 

When any work is done inside the Onan inevitably hands working in this tight space are going to hit the circuit breaker handle that is inside the Onan. This circuit breaker is connected to the control board and if tripped or off -  when you start the Onan it will start and run just fine bur NO POWER will come out of it into the Roadtrek. The AC outlets will not work, The air conditioner will not start. The TV will not start. The microwave will not start - in fact the microwave is a good place to see if the breaker is tripped or not. If the breaker is tripped and the generator is running the display screen that is always on when there is power to the microwave will be dark  and off!.  This can happen if you checked the oil or if you changed the oil - or any work was done inside the generator by you or a service tech. The service techs rarely check to see if the breaker is on when they finish working on the Onan.  Below is a diagram from the Onan manual of where the breaker is.  

 

I have made this big because this diagram should be better and it is not. There is an open space in the area the arrow is pointing at. If the breaker is on you will see a small black handle pointing to the passenger side in that  space.  If the breaker is off or tripped, you will not see anything looking up from the ground to inside this area. The handle will be hidden when pointing down. Reach in with a finger and feel for it!  Avoid the fuse which is also in this open space.  When you feel the handle. push it down and then pull it up with your fingertip.  Close up the Onan. Go in and start the Onan and check that there is power - look at the microwave display!  This is the first thing to do if your Onan is running and there is no AC power inside  the Roadtrek!

The fuse is even harder to see. It is a regular auto blade fuse - not hard to replace. You just have to find it and pull it out. There is a sticker (sometimes) on the side of this open area with an arrow pointing to the passenger side that says FUSE. If the fuse lined up with that it would be great - it doesn't. Feel for the fuse - be certain before you pull it out.   WHAT DOES THE FUSE DO?  If the fuse is BLOWN the generator DOES NOT START. It does not crank. It does nothing when you push the switch inside which does not light. IT IS DEAD!  First thing to do if this happens is check the fuse inside the Onan. If it is the fuse it saves a lot of money and trouble to get the Onan fixed or trying to fix it yourself. 

 The Onan uses one half to a third gallon of gasoline in one hour of runtime. The generator will automatically shut down if the gas tank in the van goes below 1/4 tank. This is to prevent you getting stuck with no gasoline running the generator all night.  The generator will also shut itself down if the oil level in the generator falls below full.  This prevents the generator motor burning itself out. 

If you own a Roadtrek with an Onan you already know that it is loud and it vibrates when it is running. You can feel the vibration in the floor. There is an Onan resonator that you can buy that will quiet the motor noise some.  It still vibrates.  Some have added rubber cushioning to above the Onan and where it is bolted into the bottom of the chassis and that can lower the vibration.  I have not done either.

Some may have Roadtrek's later generator system - the "underhood engine generator". This is a SECOND high power alternator installed by Roadtrek under the hood and run by a longer and different belt. The belt is not standard to the Chevy and if you have an engine generator it is advised to buy a spare belt and always have it with you in the Roadtrek.  What this does is provide generated AC power to the Roadtrek by starting and running the engine. The engine is running at idle which Chevy will tell you is not good over a span of hours but Roadtrek insisted it was not a problem. Is this quieter - only if your engine is running is quiet. There are no vibrations - that is a plus. This does use a good amount of gasoline.  Much more than the 1/2 to 2/3 gallon the Onan uses - plus there is a great deal more exhaust that will come from running the engine with more CO to come inside or drift to a neighboring RV. Roadtrek started offering the engine generator to Chevy based Roadtreks around 2015 along with some other advanced electrical system components that previously were tested and sold only on Sprinter based Roadtreks. 

Please get the manual for your Onan, print it out and keep it in the Roadtrek - or put the USB file on your phone or a USB stick to access on your computer when traveling. It goes into much more detail than I have here and it has a troubleshooting chart written out inside.