Onan 7500 Quiet Diesel fault codes

[sunlovers]

HELP!!!
Have started having problems with the generator. It has run without a problem since I installed in the bus over a year ago with only 190 hrs on it ( came out of a 2007 motorhome). Before installing I blew the radiator out with air as well as flushing it, changed the oil and filter using Onan oil and air filter.
PROBLEM:
Generator quit running about an hour out from the house on our last trip. I stopped to see what was wrong. Tried to restart but started flashing a code, blink, blink, blink-long pause-blink, blink, blink. Tried to restart again after a few min. but no luck. Took bus to Onan service center and they spent 2 hrs looking but couldn't find a thing wrong. They cleared the codes and she started right up. About 2 weeks ago started up for monthly running and NO problem. Went camping the week of the 4 th and got about 1 hr from our campground and it shut down again (didn't stop to check this time). Got set up at campground and checked generator, flashing the same fault codes again.
I am not an electrical person so ANY help would be gladly welcomed.
THANKS

[wg4t50]

Need the model number AND   The spec letter,  the letter at the end of the model number.
Dave M

[chessie4905]

  From what I understand, you were running it while you were out on the road? Did they tell you what that code indicated? Did they show you how to clear the code? Could it be overheating due to air flow issues out on the road. Were the outside temps real high those days? Have you ever run it this way before at outside cooler temps with no issues?

[chessie4905]

  Here; check this out:
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/26249506/gotomsg/26250404.cfm


  I also noticed that after code 33, you are supposed to hit the button again to get the code? (from one poster on that thread)

[Utahclaimjumper]

 I also have this generator, it has been fault free for over 2100 Hrs., lesson learned, ALWAYS remove all loads BEFORE shutting the gen. off, it gets really expensive when you blow the built in inverter.>>>Dan

[gumpy]

We need the secondary fault codes. There are several pages of secondary fault codes listed. Too many to post here. Here's the general procedure for
obtaining the secondary codes. Post them here or email them to me and I'll look them up for you.


TABLE 4. TROUBLESHOOTING lists the Fault
Codes in numerical order along with step-by-step
instructions for corrective action. If you fail to resolve
the problem after taking the corrective actions
suggested, contact an authorized Onan dealer. See
How to Obtain Service (Page 34).
First note the following:
• Maintaining engine oil level, keeping battery
connections clean and tight, watching the fuel
gauge, not overloading the genset, etc. will
prevent most shutdowns.
• When the genset and vehicle engine share a
common fuel tank the fuel dip tubes are usually
arranged so that the genset will run out of
fuel first. Marking the genset empty point on
the fuel gauge will make it easier to tell when
to stop the genset before running it out of fuel.
First-Level Fault Codes: The genset controller
provides extensive diagnostics by causing the status
indicator light on the Control Switch to blink in a
coded fashion. Following a fault shutdown, the indicator
light will repeatedly blink 1, 2 or 3 blinks at a
time.
• One blink indicates shut down due to high temperature
• Two blinks indicates shutdown due to a loss of
engine oil pressure
• Three blinks indicates shutdown due to some
other abnormal condition.
Second-Level Fault Codes: For a 1-blink or 3-blink
first-level fault code, one touch to Stop brings up a
second-level fault code. This code consists of 1, 2, 3
or 4 blinks, a brief pause, and then 1 to 9 blinks. The
first set of blinks represents the tens digit and the
second set of blinks the units digit of the fault code
number. For example, Fault Code No. 23 would appear
as:
blink-blink—pause—blink-blink-blink—...
NOTE: Fault Code Nos. 1, 2 and 3 are first-level faults.
Avoid interpreting them as second-level Fault Codes
11, 22 and 33. The pauses between repetitions of the
fault code are longer than the pauses between the
tens and units digits of the the code. For example,
Fault Code 33 would appear as:
blink-blink-blink—pause—blink-blink-blink
—longer pause—
blink-blink-blink—pause—blink-blink-blink—...

Restoring Fault Code Blinking: The fault code
stops blinking after five minutes. Press Stop three
times within five seconds to restore blinking. Note
that the last fault logged will blink, even after the
condition that caused the shutdown has been corrected.

[sunlovers]

Well lets try this again. Sent all this info Sat. around 4 pm and looks like it didn't take.

Dave, Model # HDKAJ, spec. letter-H

Chessie, dealer didn't show and wouldn't show me how to clear codes, he said they fixed the problem and didn't clear codes out. Yes I ran it severl times last summer in 90 degree weather, no problems going down the road.

Utah, I always load the gen. one thing at a time (slowly) and the same way when unloading the gen. before shutting.

Craig, I double checked codes and got secondary codes also. Rechecked everything 3 times to be sure. Fault code # 1, blink-blink-blink--pause--blink-blink-blink--pause--blink-blink-blink, longer pause the starts over. Pressed stop button and got the secondary code, 4 blinks-pause-6 blinks then a longer pause and then it repeats. I read the secondary fault code and have done everything listed in the Onan manual. My one question now, is there supposed to be a ground strap from the gen. ground (- terminal) to the bus frame or just hook up the battery to the gen. only.

Thanks again in advance for your help. I sure hopes this takes this time cause my fingers are getting tired typing this for a second time.
Mike

[wg4t50]

Mike,
Check your email, sent you what your looking for.
Let me know if it does not cover  your issues.
Dave M

[gumpy]

I have this same Onan generator in my bus.

The 46 fault code is related to the starting battery being low.  How do you have the starting battery connected? Are you using the bus
batteries to start the generator or do you have a separate battery for the generator?  Note that his generator does not have an alternator
for recharging the start battery (though that may have been an option and yours might have one). You have to charge the battery from
a separate source. It was intended to start the generator from the motorhome start batteries and recharge them with the engine alternator.

In mine, I have a separate battery for starting the generator. I have a small marine charger in the bay connected to the generator battery
which I plug in from time to time. I used to have a 12 volt wire connected to the battery from my house system, but had issues with
fuses when the battery got bad, and have not replaced the wire on the new battery.

As for grounding, if you have bolted the generator cabinet to the floor of the bay, then you are grounded to the frame. It won't hurt
anything to add a ground strap between the generator and the frame, but it shouldn't be necessary. I suppose it's possible that an
internal ground strap may be missing or broken, though I don't know how the generator is actually grounded to the case. I'm pretty
sure it's isolated by rubber vibration mounts, so would expect a ground strap. It should be sufficient to ground the negative cable connection
to the frame. (on mine, I do not have a connection from the battery to the frame, only to the generator lug). The installation manual
discusses connecting the battery on page 21. Basically, if you have a cable from the battery to the generator negative, you're good. It's
not necessary to ground the generator to the frame unless you are using the frame as ground to the battery rather than a cable.

Now, I'm suspicious that the 46 fault code is not the culprit for your generator shutting down and that you may have a couple problems
here, including the start battery not charging. You said the generator shut down on you. You need to get the codes from the generator
when it dies, before you try to restart it. I have a feeling they will be different.

However, if you are using a dedicated battery with no charging capability, it's quite possible that the battery is getting too low for the
inverter to work properly (which is kind of what the 46 fault code is indicating), in which case you need to connect the battery to
a 12v charging source (coach battery, house battery, etc).

BTW, do you have the manuals for this?  If not I can email the PDF files to you or put them on my website for you to download.

[sunlovers]

GOOD MORNING ALL!!!

Dave - I got the manual. Thanks

Craig, I have a separate battery hooked to the generator. I also have a BATTARY TENDER JR hooked up full time. The bays in the bus were cut out long ago and reinstalled with Marine plywood and painted with several coats of oil base paint to help seal the wood. The generator is mounted to a slide for service (didn't want to cut a larger hole in the floor but did cut a hole for hot exhaust air and exhaust pipe). The ground straps in the generator are good but I don't have one going from the slide to the bus frame.

[wg4t50]

What bus are you working with ?

1-Battery Tender is good.
2-A bonding/ground strap between the generator frame to the chassis is VERY recommended.
Dave M

[gumpy]

Craig, I have a separate battery hooked to the generator. I also have a BATTARY TENDER JR hooked up full time. The bays in the bus were cut out long ago and reinstalled with Marine plywood and painted with several coats of oil base paint to help seal the wood. The generator is mounted to a slide for service (didn't want to cut a larger hole in the floor but did cut a hole for hot exhaust air and exhaust pipe). The ground straps in the generator are good but I don't have one going from the slide to the bus frame.

If it's mounted on plywood, I'd probably run a ground strap from the generator negative post to the bus frame, though technically, it's not necessary with a stand alone battery which
is connected directly to the generator posts. Still not a bad idea to ground it to the frame.

I'm not familiar with a Battery Tender Jr, but looked up the specs on google. Looks like it only puts out 0.75 amps. If this is your only means of charging that starting battery,
then I'm thinking we found your problem. 3/4 amp will take a long time to replenish a battery after starting the generator, and if you've started it several times over
the course of a few days, then it's even more likely to be low.

Take a voltage reading on the battery and see where it is. Then start the generator several times and then run it with the A/Cs on and see if it will reproduce the problem by shutting
down, (or wait till the next time you use it and it shuts down). Take a voltage reading on the battery then and see where it is.

I'm guessing when it shuts down, the battery voltage will be low.

Of course the solution is to get a bigger charger and put on it or wire the battery to the house 12v system which hopefully is being fed by the inverter when the generator is running.

[Charles in SC]

Do you have to reprime it to restart it? Running for awhile then shutting off sounds like it could be the fuel filter. If you have not ever replaced it I would recommend doing it. I takes very little to stop it up. Mine is an HDKAK so it is a little different.

[gumpy]

Do you have to reprime it to restart it? Running for awhile then shutting off sounds like it could be the fuel filter. If you have not ever replaced it I would recommend doing it. I takes very little to stop it up. Mine is an HDKAK so it is a little different.

That wouldn't give a secondary fault code 46.  it's related to the battery being low.

Also has an electric fuel pump so no repriming necessary.

[sunlovers]

Good morning all!!!

Craig,
I will run the ground strap from the gen. ground (-) terminal to the frame. I have the Tender Jr. running 24-7. Every time I check it says it is fully charged. May return this one and get the next size bigger. I am going to check the voltage on the battery to see what is going on and may even pull it and have it checked out.
Also, in all the posting no one has said how to clear the codes on this generator, any ideas??
thanks