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replacing dead onan [message #305555] Thu, 18 August 2016 10:00 Go to next message
Bob S. is currently offline  Bob S.   United States
Messages: 143
Registered: October 2012
Location: Rapid City, SD
Karma: 2
Senior Member
Hello everyone, In a post last week I asked for some help in diagnosing my non-working generator. Unfortunately I was unable to determine what was wrong with it so I took it to a shop. Diagnosis was a short in the rotor. Obviously not worth the money to repair it. I was able to secure a used Onan QG 4.0 with only 140 hours on it. I only have one roof A/C so this should be adequate. This genset is an EVAP model, which I'm told meets California emission standards. My question is: does anyone have any experience or knowledge in retrofitting one of these in a GMC. Will it hook right up to existing fittings or does the EVAP require anything special to make it run. I live in South Dakota and there are no EPA checks or requirements for vehicles, so if I have to disable the EVAP system, it is legal. Any and all guidance and information is will be greatly appreciated.


Bob and Pam Schilling Rapid City, SD "78 Royale
Re: [GMCnet] replacing dead onan [message #305556 is a reply to message #305555] Thu, 18 August 2016 10:40 Go to previous messageGo to next message
powerjon is currently offline  powerjon   United States
Messages: 2446
Registered: January 2004
Karma: 5
Senior Member
Bob,
Unknown if this particular unit has been installed in our motorhomes.
http://www.norwall.com/products/Cummins-Onan-QG-4-0-Gasoline-RV-Generator-4.0KYFA-26100

See this for dimensions:
http://www.norwall.com/product_pdfs/9410_4_0kyfa_26100_specs.pdf

Owners Manual:
http://www.norwall.com/product_pdfs/6604_ky_spec_p__opm_2015.pdf

Service Guide:
http://www.norwall.com/product_pdfs/4807_4_0kyfa_26100_service.pdf

Installation Guide:
http://www.norwall.com/product_pdfs/1103_ky_spec_p_install_2015.pdf

This guide has a lot of very good information that may be helpful. Read section 3.3 for ventilation. Also see Fig. 5 in that section

JR Wright
78 Buskirk Stretch
75 Avion
Michigan

> On Aug 18, 2016, at 11:00 AM, Bob Schilling wrote:
>
> Hello everyone, In a post last week I asked for some help in diagnosing my non-working generator. Unfortunately I was unable to determine what was
> wrong with it so I took it to a shop. Diagnosis was a short in the rotor. Obviously not worth the money to repair it. I was able to secure a used Onan
> QG 4.0 with only 140 hours on it. I only have one roof A/C so this should be adequate. This genset is an EVAP model, which I'm told meets California
> emission standards. My question is: does anyone have any experience or knowledge in retrofitting one of these in a GMC. Will it hook right up to
> existing fittings or does the EVAP require anything special to make it run. I live in South Dakota and there are no EPA checks or requirements for
> vehicles, so if I have to disable the EVAP system, it is legal. Any and all guidance and information is will be greatly appreciated.
>
> --
> Bob and Pam Schilling
> Rapid City, SD
> "78 Royale

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J.R. Wright
GMC GreatLaker
GMC Eastern States
GMCMI
78 30' Buskirk Stretch
75 Avion Under Reconstruction
Michigan
Re: replacing dead onan [message #305562 is a reply to message #305555] Thu, 18 August 2016 11:53 Go to previous messageGo to next message
JohnL455 is currently offline  JohnL455   United States
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Registered: October 2006
Location: Woodstock, IL
Karma: 12
Senior Member
Just my 2 cents, but isn't it the field that usually fails? Perhaps Mr Miller will chine in. Did they meter out of circuit? I would think good rotors from junked engine units could be had, retaining the Powerdrawer convenience .

John Lebetski
Woodstock, IL
77 Eleganza II
Re: [GMCnet] replacing dead onan [message #305572 is a reply to message #305562] Thu, 18 August 2016 19:07 Go to previous messageGo to next message
Jim Miller is currently offline  Jim Miller   United States
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Registered: March 2008
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Senior Member
On Aug 18, 2016, at 12:53 PM, John R.Lebetski wrote:

> Just my 2 cents, but isn't it the field that usually fails? Perhaps Mr Miller will chine in. Did they meter out of circuit? I would think good
> rotors from junked engine units could be had, retaining the Powerdrawer convenience .

Hi John,

Based on my experience in helping people troubleshoot their units - in addition to the many that I've repaired - the field assembly is almost always the culprit. I’ve only seen one bad armature and it was open rather than shorted. Shorted armatures tend to have a low output voltage and develop a LOT of heat - open ones have no output.

The original poster did not specify any details other than it was “non-working” so it is tough to draw any conclusions. It would be interesting to know what test procedures his shop followed in order to arrive at their “shorted armature” diagnosis.

—Jim
Jim Miller
1977 Eleganza
1977 Royale
Hamilton, OH




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Jim Miller 1977 Eleganza II 1977 Royale Hamilton, OH
Re: replacing dead onan [message #305576 is a reply to message #305555] Thu, 18 August 2016 21:44 Go to previous messageGo to next message
JohnL455 is currently offline  JohnL455   United States
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
Senior Member
What Ohms should you see slip ring to slip ring? Did they remove brushes? Not sure if you don't if you are reading compounding reactor and or bridge? Did they have meter on correct scale and know how to use it ? Sounds fishy.

John Lebetski
Woodstock, IL
77 Eleganza II
Re: [GMCnet] replacing dead onan [message #305584 is a reply to message #305555] Fri, 19 August 2016 01:45 Go to previous messageGo to next message
jimk is currently offline  jimk   United States
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Registered: July 2006
Location: Belmont, CA
Karma: 9
Senior Member
The main thing yo need is the wire harness for inside control.
The electrical power is all very similer.
Hope you know what holes you need below to
i'm not familiar about the evap system.

On Thu, Aug 18, 2016 at 8:00 AM, Bob Schilling
wrote:

> Hello everyone, In a post last week I asked for some help in diagnosing my
> non-working generator. Unfortunately I was unable to determine what was
> wrong with it so I took it to a shop. Diagnosis was a short in the rotor.
> Obviously not worth the money to repair it. I was able to secure a used Onan
> QG 4.0 with only 140 hours on it. I only have one roof A/C so this should
> be adequate. This genset is an EVAP model, which I'm told meets California
> emission standards. My question is: does anyone have any experience or
> knowledge in retrofitting one of these in a GMC. Will it hook right up to
> existing fittings or does the EVAP require anything special to make it
> run. I live in South Dakota and there are no EPA checks or requirements for
> vehicles, so if I have to disable the EVAP system, it is legal. Any and
> all guidance and information is will be greatly appreciated.
>
> --
> Bob and Pam Schilling
> Rapid City, SD
> "78 Royale
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>



--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
Re: replacing dead onan [message #305594 is a reply to message #305555] Fri, 19 August 2016 08:30 Go to previous messageGo to next message
Bob S. is currently offline  Bob S.   United States
Messages: 143
Registered: October 2012
Location: Rapid City, SD
Karma: 2
Senior Member
I appreciate all the advise and suggestions. I took my generator to the Cummins Onan dealer here. As I said in my original post I am completely ignorant of anything having to do with the electrical side of the generator. Unfortunately I have to rely on the diagnosis of the technician as I do not have the knowledge to verify his findings, or even ask intelligent questions that would make me feel more comfortable. I'm going on blind trust and optimism that his diagnosis is correct. The links that were provided in a previous post will be helpful when I install it. I am trying to find someone that can tell me if the I can disable or bypass the EVAP system as it is only required in the state of California. It appears that if it is can not be bypassed I may have to install a charcoal vapor canister and a fuel return line. I will hopefully be able to learn a little more about the crazy stuff developed for the great state of California. Once again thanks to everyone for your help.

Bob and Pam Schilling Rapid City, SD "78 Royale
Re: replacing dead onan [message #305596 is a reply to message #305555] Fri, 19 August 2016 09:47 Go to previous messageGo to next message
lqqkatjon is currently offline  lqqkatjon   United States
Messages: 2324
Registered: October 2010
Location: St. Cloud, MN
Karma: 5
Senior Member
Bob,

Call this guy:

http://minnesota.rvgeneratorrepair.com/rv.html



You should be able to fire it up and do alot of test running of the generator before you put it in the coach. I doubt the EVAP system will cause any issues if removed.



Jon Roche 75 palm beach EBL EFI, manny headers, Micro Level, rebuilt most of coach now. St. Cloud, MN http://lqqkatjon.blogspot.com/
Re: replacing dead onan [message #305598 is a reply to message #305555] Fri, 19 August 2016 10:33 Go to previous messageGo to next message
jhbridges is currently offline  jhbridges   United States
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Registered: May 2011
Location: Braselton ga
Karma: -74
Senior Member
I'd keep the original Onan as well. You can learn by disassembling it to replace the alternator rotor, if that's what's truly shot. Set it in the garage, go get a cheap VOM (meter) and report back. You can do the tests and report back here, and the gurus (Miller) can advise based on results. With the new one installed there would be no hurry.
We ran a couple of those new ones, both 2 and 4 kw, in Econoline vans. The early 2 (or 2.5, don't remember) had some problems but Onan got them corrected in the later ones. They are, unfortunately, a 3600 rpm genset.

--johnny


Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons. Braselton, Ga. I forgive them all, save those who hurt the dogs. They must answer to me in hell
icon3.gif  Re: replacing dead onan [message #305606 is a reply to message #305555] Fri, 19 August 2016 13:07 Go to previous messageGo to next message
Bob S. is currently offline  Bob S.   United States
Messages: 143
Registered: October 2012
Location: Rapid City, SD
Karma: 2
Senior Member
Thanks again for all the information and help. I just picked up my coach and had an opportunity to speak with the technician. He thoroughly explained what he did to reach his diagnosis and I feel comfortable that he is correct. With the help of the links to the manuals, listed in the earlier post, and the offer of the technician to give me guidance( should I need it) I think the installation should go somewhat smoothly. Famous last words!!!

Bob and Pam Schilling Rapid City, SD "78 Royale
Re: replacing dead onan [message #305672 is a reply to message #305555] Sat, 20 August 2016 17:01 Go to previous message
JohnL455 is currently offline  JohnL455   United States
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Registered: October 2006
Location: Woodstock, IL
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Good luck on the install. In a way new is good but the old ones have proved to be workhorses. I have to think the Powerdrawer is taged as "obsolete" by most Onan shops especially since Cummins bought them out.

John Lebetski
Woodstock, IL
77 Eleganza II
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