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.