2006 FreeSpirit Onan 2500 LP generator won't crank

LoopM

New member
Hiya! I've got a 2006 FreeSpirit with an Onan 2500 LP generator that won't crank. It won't even click. Both at the remote starter switch and at the generator access panel starter switch. The oil was quite low, so I changed both the oil and the air filter. Still no crank. The manual says that with no crank, it is either 1) low battery 2) blown fuse 3) bad battery connection. The internet seems to only describe cases of cranking, but not starting. I've checked lots of fuses, and none are blown. The 5 amp fuse on the generator is intact. Just for fun, I tried swapping the generator fuse with another known good fuse (7.5A, don't shoot me) and still no crank. The electrical connection to the generator is just about impossible to diagnose because it's inaccessible. I was able to shine my phone flashlight into the vent holes on the left side of the front of the generator and the electrical connections looked intact. Not like a rodent had gotten in there and partied like rodents do or anything.

Bonus information: The last time it worked was a few weeks ago. We were on a trip back to the PNW from the midwest. The day before, the generator was fired up for a few minutes to use the microwave at a rest stop or a gas station, and then shut off. It was then determined it was needed for something else, so it was fired up very soon after it had been shut down. This was the last time it was able to crank. Did this quick restart cause the end of our gen?

Please, how do we get our crank back?
 

Grouser

Active member
I'm not sure if there's a way to spin the crankshaft by hand to see if it's froze up or stuck. Or maybe your starter just died. They do that. One time they work, next time they don't. Try to make sure you're getting power to the starter, and then tap it with a mallet or something ,,,,sometimes the solenoid get a little moisture in them and gets stuck. The light tap frees it up.
 

LoopM

New member
There's not a way to spin it by hand. I banged on it a bit and no luck.

I measured the voltage across the 5A fuse port with the fuse out and the start switch engaged, and it is 6.3V. Should it be 12V at this location? Or is the voltage stepped down at this fuse location for some reason?

Both house batteries are measuring >12V, and the wires feeding an overhead light are reading 12.3V.
 

bcislander

'07 Mercedes-badged Dodge
There's not a way to spin it by hand. I banged on it a bit and no luck.

I measured the voltage across the 5A fuse port with the fuse out and the start switch engaged, and it is 6.3V. Should it be 12V at this location? Or is the voltage stepped down at this fuse location for some reason?

Both house batteries are measuring >12V, and the wires feeding an overhead light are reading 12.3V.
If I understand correctly, it would appear that you placed your voltmeter across the fuse terminals, with the fuse out. If this is the case, then you have placed your voltmeter in series with the Onan starter windings. The voltage you measured is approximately half of the supply voltage, which indicates that the starter winding is a very high resistance, given that most modern voltmeters have a resistance of at least 1M-ohm. In short, it would appear that your Onan starter winding is essentially an open circuit, or the connections (positive and ground) to the winding have opened.

I would expect the resistance of Onan starter to be a few ohms at most. To verify, measure the resistance from the starter side of the fuse holder to ground, with the fuse removed.
 

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