Onan Basics
Where is my Onan?
It all
depends! What year and model is
your Roadtrek? We know of three
possible locations. All have their
advantages and disadvantages.
Dodge
– Before mid-1996. Roadtrek put
the Onan in a metal lined compartment under the
dinette on the driver’s side in the rear. This was a great spot with easy access
to the generator.
The
disadvantage is that if the generator must be removed it involves several dozen
screws and access to the dinette.
There are a few tricks to getting the generator out of the compartment
easily (it is heavy).
Chevy
– Before mid-1996.
Unfortunately
the Chevys had the gas fuel fill in the generator location, so the generator
compartment had to be deeper (which was why the Chevys lacked the under floor
trunk). When the access door
is opened the access to the generator is partly blocked by a metal box
enclosing the fuel fill line.
Needless to say servicing the generator around
this obstruction leaves a lot to be desired.
Post mid-1996 Dodges & Chevys and all Sprinters. The Onan generator is located in the center rear
underneath. This exposes the Onan to the elements but Class Bs
are a compromise and that means sometimes things are not in the most convenient
places.
You can
see why rust and bad ground connections plague Onan
generators installed in the path of road salt and grime.
Where the
Heck is the …?
Every
Roadtrek owner should be able to (as a minimum) check
the oil level and reset the circuit
breaker on the Onan. If you are physically unable to do this,
carry some photos so you can instruct someone else on what to do.
Outside View. If
you have the center rear underneath installation you will see something like
this when you crawl under your Roadtrek in the rear. It is from the outside you reach the
spark plug and the oil drain.
To open
the access panel put your fingers in the latches and pull up and out. Remember the latches are at the bottom
of the panel.
Behind the Access Panel. Once the
access panel is opened, this is what you see:
Notes:
The altitude adjustment is the main mixture adjustment. Do not run the generator for long with
the access panel cover off. It
affects the air flow for cooling.
Carburetor Parts. Here are the
carburetor parts identified.
Notes:
The idle mixture adjustment is hidden under a cap. It is not supposed to be touched. It is clogged idle jets from lack of use
that probably create the most problems with Onans. The Onan
manual says to run the generator for two hours every month under ½ load (the air conditioner or a small electric heater will
create such a load). Roadtrek says
one hour a month. An Onan Rep told an audience of Roadtrek owners that 20
minutes was enough IF you ran it at ½ load, since that was really all it
took to bring everything up to operating temperature and dry out any moisture.
HELP!
My Onan Doesn’t Work!
Click here for
Troubleshooting Tables
How do I
…?
Reset the Onan Circuit
Breaker?