Onan Generator Help Please! SPEED SENSE FAULT CODE NO 45

kmarvin88 · Joined: 03 Aug 2008 Posts: 2 Location: ny

My generator will not stay running. It is an Onan Microquiet 4000 model 4KY FA26100J. The generator starts and then stalls out as if the fuel tank is too low. I receive error code of 45. It even stalls if I hold down the starter button.

So far I replaced the fuel filter, and air filters and changed the oil (needed them for maintenance anyway).

Can anyone give me insight on other troubleshooting steps?

gbtate · Joined: 16 Aug 2008 Posts: 8

We have a older Mallard Class C motorhome with an Onan generator too. In the owner's manual, it states that the generator cannot be run when the fuel level in the RV is below a quarter of a tank. The motorhome and the generator both are fueled by the same gas tank... and this is simply a safety feature, so you won't run out of gas sitting at a camping spot and not be able to get to a gas station. It actually makes good sense.
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G. B. Tate

Eblouix · Joined: 16 Aug 2008 Posts: 1

Hi,
I got a similar problem with my Onan generator and it was simply due to the rubber hose or tubing connecting the fuel tank to the generator was cracked. When this happens, the safety valve permitting gas to get through is simply not opening because the air pressure is not going down, and this causes the generator to crank but not starting since no gas is filling the carburetor.
So, I suggest that that you check this tubing and eventually replace it.
Hope it will help. Let me know.

Bye!

bonnie3 · Joined: 31 May 2006 Posts: 95 Location: Napoleon Oh

Wow! Go newbies and welcome to the group!
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geomusic · Joined: 16 Aug 2008 Posts: 4 Location: Sarasota, FL

I think the generator is designed that way - at least that's what the book says. When the fuel tank is less than 1/3 (or 1/4 - I forget) full, the generator stops running to guard against running out of fuel if you're out boondocking. You still have enough gas to get somewhere to fill up. George

wb0ixs · Joined: 16 Aug 2008 Posts: 1

Greetings. Your problem sounds something like a problem that I had when I bought my generator. It was new and would start and run for a short time. I found the problem when I checked the Low Oil Sensor. You don't have to take it off to check, just unplug the wire going to it. Good luck.

kmarvin88 · Joined: 03 Aug 2008 Posts: 2 Location: ny

Thank you for your responses. Yes the generator will not operate under a 1/4 tank by design. This generator will not stay running no matter what the tank level. It is getting enough fuel to start right up, but it shuts down almost immediately.

I read somewhere that if you hold down the start button, it bypasses the kill sensors and the generator will stay running if this is a sensor issue. Anyone know if this is true? Mine dies even if I hold the button. Always runs for about 3 seconds and then shuts down with a 45 error code.

Thanks,
Ken
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2000 Itasca Spirit 29 ft.

geomusic · Joined: 16 Aug 2008 Posts: 4 Location: Sarasota, FL

Ken, have you checked the reset button on the generator?
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George
2004 Coachmen Concord

tantamount · Joined: 15 Apr 2007 Posts: 211 Location: roaming

Have you checked Onan's website for clarification of the fault code, and/or asked THEM for advice?

Charles · Joined: 24 Sep 2008 Posts: 1 Location: Sweet Home Alabama

Well, I finally bought an old RV after many years of tent camping. Now in my 50s and picking up weight like there is no tomorrow, I decided that me and the old lady had better get something to get us back into camping to help us get more active again. So I am lined up with my neighbor to purchase his old '88 Itasca Windcruiser. Well, it's a good thing that I am a shadetree mechanic because it looks as if I have my work cut out for me (not a bad thing, I need the exercise). Yes, I intend to buy a newer RV when I am no longer willing to put some time into this one, but by then maybe I will be a better and more learned RVer. Well, it ain't the prettiest thing in the world and there is no slideout, but we have no kids and it's just the two of us, so with a little TLC and elbow grease it should shine up pretty well. I think this is a good first purchase.

The first thing that is on my fix list is the Onan generator which I am sure has to be a sensor after reading this forum. The generator runs fine as long as you hold down the start button. Hopefully I can determine which sensor it is by plugging or jumping. I have checked out the Onan website and it looks as if they will be very helpful, even having online manuals.

Next is tackling the oxidation on the fiberglass. Does anyone have a favorite wondergel that will help remove heavy oxidation and protect the gelcoat paint? Or is there a better way to remove the oxidation and bring back the old luster?

Third is the headliner, which reveals water leaks at some point in history. The thing has a solid stainless steel top, but of course where there is an opening, water will soon follow. I feel I can handle this pretty well with some fresh gaskets (I hope this is easy, sheesh). But there are stains; my first inclination is a steam cleaner, but I don't want to make matters worse. Any advice?

Hey, I hope to meet some of you on the road by next fall, that's about when this thing may be ready for a long trip. I feel fairly safe with new tires, belts, and brakes, but much detail to work out. If any of you have any friendly advice, I welcome it with much thanks.

Take care,
Charles
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Chuck

jfran304 · Joined: 19 Feb 2008 Posts: 114 Location: Warner Robins, GA

Another thing to check is your adjustment for altitude. On my 03 Onan I would have to change the adjustment when I went from GA to NV.

It would run as long as I held down the start button but quit as soon as I let it go.

Good Luck,
Jon
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Jon & Sue Francis

brettr · Joined: 06 Oct 2008 Posts: 6

Did you ever figure out what fault code 45 was? I am having the same problem.

Akfishkid · Joined: 07 Apr 2008 Posts: 27 Location: Antioch, Ca

Charles,
Found some stuff for fiberglass that's really great. They have a kit that has cleaner, tools, and a wipe on coating that puts an unbelievable gloss on the gelcoat. I am in no way connected to this company. Our FMCA group just bought 17 of these kits in a group buy. They gave us a good discount for the volume we ordered. The website is www.newglass2.com The dealer is in Florida and markets this stuff to the marine folks. Good luck!
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Wanderer · Joined: 24 Mar 2008 Posts: 7

First, I would call Onan to get the word from them. They have been very helpful to me whenever I have a question.

Second, I did not see anything about the requirement to run your generator each month so the generator carburetor does not varnish with old gas. You didn't mention what your usage of the generator was. If you haven't used your generator for sometime without running it, you could very easy have a starting problem. Just a thought.

Smile

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Trying to keep Safe and have fun.

porscheracer · Posted: Mon Oct 27, 2008 2:14 pm Post subject:

Mine varnished up once due to improper run maintenance. I was able to get it functioning by manually fooling with the choke and throttle long enough to get it to stay running (took a few minutes). After it warmed up, I put a load on it and ran it for ~ an hour with clean fuel.
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Probably somewhere in NA - or maybe on another continent.