Onan Microlite 2800 Will Not Start

mstevenson wrote:
Far as I have read they will not stay running if not producing electricity but the worrisome part is why it will not start in the first place unless I jump the starter. If I could get her started a little easier I could worry about the voltage issue but at this point if it cannot be started without jumping it would be useless for me to worry about the voltage issue I think anyway

How are you "jumping the starter"? If you're energizing the starter solenoid relay, a momentary switch addition would fix that.
If you're connecting 12V power directly to the starter power inlet, there may be more amiss than a wiring snafu.

A wiring schematic would be my first step. Good luck!

The guys on smokstak.com, in the ONAN section, can probably send you or link you to a manual for Spec "K". "Won't Crank" has got to be near the top of any troubleshooting flowchart.

Far as I have read they will not stay running if not producing electricity but the worrisome part is why it will not start in the first place unless I jump the starter. If I could get her started a little easier I could worry about the voltage issue but at this point if it cannot be started without jumping it would be useless for me to worry about the voltage issue I think anyway

OK... on these ONAN gensets, various operational tests are bypassed when starting. as in holding the switch to START. Larger gensets have oil pumps, and oil pressure, oil level sensors were bypassed till you released the switch to RUN.

Don't hold me to this, but I think 4KY (28KV probably similar) won't keep running if it isn't producing electricity. They have less oil-related safeties since they're splash-lubed, but I'm pretty sure it has to be producing AC, and possibly also a 12VDC output to recharge the coach battery that starts it.

I can start it jumping to start long as I am holding the start switch. Soon as I release it dies and it is not producing electricity either when running but figured I would start and the non-starting issue first. Runs good does not hunt much when running.

Is the genset far enough away from anything that's a fire or explosion risk? If so, try jumping the starter motor direct to 12VDC. Since the 2800 has a logic board, I think I'd disconnect the 12VDC "Hot" side from the rest of the generator for the start attempt.

Gas fumes or spills are obvious risks, but so is a Battery. Work too close to one and sparks can cause an explosion from battery gases.

THANKS for posting Model and Spec. Many don't.

This Link is for up to Spec "D" but might be of some help to you.

OH, as you check power and wiring, never neglect the GROUND. All too often we spend our troubleshooting on only the HOT side of the circuit.

Oh another thing, when I engage the start button on the control board the fuel pump does engage so it seems to me like the starter should also be engaging...

I have left these disconnected and I can get the generator to start and run if I jump the starter and hold in the start on the control board. Simply trying to use the start switch will not turn over the starter. I have checked voltage to the solenoid and I am not getting anything there to engage it. I have checked both side of the fuse to ensure there is good contact. Not sure where to go from here. Thanks for your help guys, I was hoping these wires were simply for the remote start.

If you have a start/stop switch on the generator itself, you can probably ignore these four mysterious wires as they're probably for a remote start panel, as stated, the functions of which are duplicated by the switch on the generator itself.

For what it's worth, the Onan generator I have (a different model) does use four wires for the remote switch: a ground, a start signal (that is grounded when the switch is pushed on the start side), a stop signal (grounded when the switch is pushed the other way on the stop side), and +12V power lead for the hour meter and running indicator light. (The switch is a single pole double throw momentary center off rocker switch.)

You do need to have +12V connected to the generator, I've seen on the starter solenoid, and chassis ground, and this needs to be a pretty hefty connection as the starter uses a good bit of current. Obviously there are also 120V connections for the power output.

Most "non starting" generator post imply it turns over and won't start - assume yours is "disconnected generator - how to connect"?

Find a schematic and don't assume that your black wire is "ground".