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| Onan starting [message #311934] |
Mon, 09 January 2017 19:54  |
kwharland
Messages: 246
Registered: November 2005
Location: Central Florida
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I've spent over an hour searching through multiple pages of search results with no luck so I will just my question straight out. When I start my genset from either switch, it dies as soon as I release the switch. I know I've read about this problem before but the only thing I remember was it will do that if it's low on oil. Mine is not so I'm left searching for a solution.
Anyone?
Thanks,
Ken
1978 Eleganza II
[Updated on: Mon, 09 January 2017 20:04] Report message to a moderator |
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| Re: [GMCnet] Onan starting [message #311935 is a reply to message #311934] |
Mon, 09 January 2017 19:57  |
sgltrac
Messages: 2797
Registered: April 2011
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http://www.bdub.net/oddsnends.html
Check that out.
Sully
77 eleganza 2
Seattle
On Mon, Jan 9, 2017 at 5:55 PM Ken Harland wrote:
> I've spent over an hour searching through multiple pages of search results
> with no luck so I will just my question straight out. When I start my
>
> genset from either switch, it dies as soon as I release the switch. I
> know I've read about this problem before but the only thing I remember was
> it
>
> will do that if it's low on oil. My is not so I'm left searching for a
> solution.
>
>
>
> Anyone?
>
>
>
> Thanks,
>
> Ken
>
> --
>
> 1978 Eleganza II
>
>
>
> _______________________________________________
>
> GMCnet mailing list
>
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Sully
77 Royale basket case.
Future motorhome land speed record holder(bucket list)
Seattle, Wa.
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| Re: [GMCnet] Onan starting [message #311936 is a reply to message #311935] |
Mon, 09 January 2017 19:58 |
sgltrac
Messages: 2797
Registered: April 2011
Karma: 1
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Sorry, thought it was a more direct link. Try this
http://www.gmcws.org/Tech/dsimmons/onan/onan.html
On Mon, Jan 9, 2017 at 5:57 PM Todd Sullivan wrote:
> http://www.bdub.net/oddsnends.html
>
> Check that out.
>
> Sully
> 77 eleganza 2
> Seattle
>
> On Mon, Jan 9, 2017 at 5:55 PM Ken Harland
> wrote:
>
> I've spent over an hour searching through multiple pages of search results
> with no luck so I will just my question straight out. When I start my
>
> genset from either switch, it dies as soon as I release the switch. I
> know I've read about this problem before but the only thing I remember was
> it
>
> will do that if it's low on oil. My is not so I'm left searching for a
> solution.
>
>
>
> Anyone?
>
>
>
> Thanks,
>
> Ken
>
> --
>
> 1978 Eleganza II
>
>
>
> _______________________________________________
>
> GMCnet mailing list
>
> Unsubscribe or Change List Options:
>
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
>
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Sully
77 Royale basket case.
Future motorhome land speed record holder(bucket list)
Seattle, Wa.
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| Re: [GMCnet] Onan starting [message #311937 is a reply to message #311936] |
Mon, 09 January 2017 20:01 |
sgltrac
Messages: 2797
Registered: April 2011
Karma: 1
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I really miss Duane. Never met him but sure talked to him on the phone a
bunch.
Sully
77 eleganza 2
Seattle
On Mon, Jan 9, 2017 at 5:58 PM Todd Sullivan wrote:
> Sorry, thought it was a more direct link. Try this
>
> http://www.gmcws.org/Tech/dsimmons/onan/onan.html
>
> On Mon, Jan 9, 2017 at 5:57 PM Todd Sullivan wrote:
>
> http://www.bdub.net/oddsnends.html
>
> Check that out.
>
> Sully
> 77 eleganza 2
> Seattle
>
> On Mon, Jan 9, 2017 at 5:55 PM Ken Harland
> wrote:
>
> I've spent over an hour searching through multiple pages of search results
> with no luck so I will just my question straight out. When I start my
>
> genset from either switch, it dies as soon as I release the switch. I
> know I've read about this problem before but the only thing I remember was
> it
>
> will do that if it's low on oil. My is not so I'm left searching for a
> solution.
>
>
>
> Anyone?
>
>
>
> Thanks,
>
> Ken
>
> --
>
> 1978 Eleganza II
>
>
>
> _______________________________________________
>
> GMCnet mailing list
>
> Unsubscribe or Change List Options:
>
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
>
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Sully
77 Royale basket case.
Future motorhome land speed record holder(bucket list)
Seattle, Wa.
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| Re: [GMCnet] Onan starting [message #311940 is a reply to message #311938] |
Mon, 09 January 2017 20:31 |
sgltrac
Messages: 2797
Registered: April 2011
Karma: 1
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Senior Member |
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Ken,
Read the trouble shooting guide by Duane Simmons that I sent the link to.
Even if you read it slowly several times it will
Only take a few minutes. Then print it out and go out to your Onan and go
through the steps. There is no Onan issue he did not know about.
Sully
77 eleganza 2
Seattle
On Mon, Jan 9, 2017 at 6:25 PM A. wrote:
> kwharland wrote on Mon, 09 January 2017 19:54
>
>> I've spent over an hour searching through multiple pages of search
> results with no luck so I will just my question straight out. When I start
> my
>
>> genset from either switch, it dies as soon as I release the switch. I
> know I've read about this problem before but the only thing I remember was
> it
>
>> will do that if it's low on oil. Mine is not so I'm left searching for
> a solution.
>
>>
>
>> Anyone?
>
>>
>
>> Thanks,
>
>> Ken
>
> The first thing that comes to my mind is the voltage regulator. When the
> Onan starts running, the control board gets something like 28VAC on pin 8
>
> from the flywheel alternator. That tells the board that the Onan is
> running. If it doesn't get that voltage, it shuts off the fuel pump and the
>
> ignition. A faulty voltage regulator can pull that voltage down.
>
>
>
> The second thing that comes to mind is the low oil pressure sender. A bad
> sender will ground pin 12 and shut it down.
>
>
>
> A bad control board will cause grief too.
>
>
>
> Common troubleshooting technique is to jumper pin 5 to pin 9. That
> bypasses the "not running" and "low oil pressure" protections. Try it and
> see if
>
> it continues to run. If it does, you need to figure out if it is a bad
> board, a bad voltage regulator, or a bad oil pressure sending unit. Read the
>
> GMCWS link posted previously to understand how to do that.
>
> --
>
> 73 23' Sequoia 4 Sale
>
> 73 23' CanyonLands Parts Unit 4 Sale
>
> Upper Alabama
>
> "Highest price does not guarantee highest quality."
>
>
>
> _______________________________________________
>
> GMCnet mailing list
>
> Unsubscribe or Change List Options:
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Sully
77 Royale basket case.
Future motorhome land speed record holder(bucket list)
Seattle, Wa.
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| Re: [GMCnet] Onan starting [message #311942 is a reply to message #311934] |
Mon, 09 January 2017 23:15 |
Olly Schmidt
Messages: 1265
Registered: February 2014
Location: Germany and Scottsville, ...
Karma: 8
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Senior Member |
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Ken,
the first time I had contact with an Onan it was missing oil, the 2nd
time an Onan didn't fire up was due to not enough fuel. Less than
quarter full or something.
--
Best regards
Peer Oliver Schmidt
PGP Key ID: 0x83E1C2EA
'76a Eleganza II, VA
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Best regards
Olly Schmidt
PGP Key ID: 0x18a9 3a1f 4196 bf22
'76a Eleganza II, VA
'73 Sequoia, SH, Germany
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| Re: [GMCnet] Onan starting [message #311955 is a reply to message #311935] |
Tue, 10 January 2017 10:36 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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Senior Member |
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Also try pumping 9-11.
If that works, order a new board, you can go to our sight and see, or call
other GMC shops.
On Tue, Jan 10, 2017 at 8:34 AM, Jim Kanomata wrote:
> WE find that in that case to install a new board as the relay on the board
> is not latching.
>
>
> On Mon, Jan 9, 2017 at 5:54 PM, Ken Harland
> wrote:
>
>> I've spent over an hour searching through multiple pages of search
>> results with no luck so I will just my question straight out. When I start
>> my
>> genset from either switch, it dies as soon as I release the switch. I
>> know I've read about this problem before but the only thing I remember was
>> it
>> will do that if it's low on oil. My is not so I'm left searching for a
>> solution.
>>
>> Anyone?
>>
>> Thanks,
>> Ken
>> --
>> 1978 Eleganza II
>>
>> _______________________________________________
>> 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
>
--
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
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| Re: Onan starting [message #311958 is a reply to message #311934] |
Tue, 10 January 2017 10:50 |
jhbridges
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
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Senior Member |
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Low oil pressure or failure of the relay will create this problem. If jumping 9 to 5 allows the set to run, then the options are the relay isn't pulling in or the oil pressure switch isn't opening. Follow Duane's suggestions to determine which is the case. If the problem is the relay on the board, either it isn't getting voltage or the relay itself has failed. If the genset alternator is producing AC, then a measurement across the relay coil will show voltage or no voltage. If there's voltage but the relay doesn't pull in, replace it. If there's no voltage, start checking components on the card, or just simply 'shotgun' them.
Check for shorted wires anywhere on the set. I have found the relay armature melted off due to a short in the past.
--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
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| Re: Onan starting [message #312001 is a reply to message #311934] |
Tue, 10 January 2017 18:33 |
kwharland
Messages: 246
Registered: November 2005
Location: Central Florida
Karma: 0
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Senior Member |
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Thanks to all that replied, I'm sure that armed with this tips I'm sure to find my problem. Hopefully will get to it tomorrow.
Ken
1978 Eleganza II
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| Re: Onan starting [message #312142 is a reply to message #311934] |
Mon, 16 January 2017 07:56 |
kwharland
Messages: 246
Registered: November 2005
Location: Central Florida
Karma: 0
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Senior Member |
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Thanks again for all the help, here's what I know.
I have oil pressure and the oil pressure switch works fine as does a new one I bought.
Jumping pins 5 & 9 on the control board bypasses several error conditions, not just low oil pressure which is why I now have a spare oil pressure switch.
The generator doesn't stay running because I don't not have 28 volts on pin 11 which points to a possible voltage regulator issue but not exclusively. Duane's troubleshooting tips seems to be incomplete as it describes removing and insulating the connectors to it but then it stops there with no further info on a next step if there is one. Is there a further test of the regulator?
1978 Eleganza II
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| Re: Onan starting [message #312144 is a reply to message #311934] |
Mon, 16 January 2017 09:08 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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I don't think he went into testing the regulator becsuse that is what is being taken out of circuit. The two wires on the "twofer" stay connected and taped up. Remove spray clean and reseat all the faston terminals as they can be oxidized. Also the solders can be bad on the tabs to the board from vibration. Pull the board and examine the back side with light and magnifier. 90% of problems can be found here. Also check fuse tabs solder and clean where the contact fuse. Also be sure fuse is not oversized. Burnt traces can be repaired with jumpers if you are good at bench tech basics.
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: Onan starting [message #312151 is a reply to message #312142] |
Mon, 16 January 2017 10:24 |
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Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
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kwharland wrote on Mon, 16 January 2017 08:56Thanks again for all the help, here's what I know.
<snip>
The generator doesn't stay running because I don't not have 28 volts on pin 11 which points to a possible voltage regulator issue but not exclusively. Duane's troubleshooting tips seems to be incomplete as it describes removing and insulating the connectors to it but then it stops there with no further info on a next step if there is one. Is there a further test of the regulator?
Ken,
It could be, but it is unlikely that the absents of the "run signal" from the flywheel alternator is a regulator issue. Check between pins 8 and 11. Do you see a 20+VAC there when the unit is running??
If yes, you dodged one bullet.
If no, chase the wires for the two that come out from under the flywheel. Very carefully separate them from their attachments and then test the alternator winding for continuity.
If there is a winding there (forgotten what resistance it should show, but not a lot) then start looking for the bad connection.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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| Re: [GMCnet] Onan starting [message #312152 is a reply to message #312145] |
Mon, 16 January 2017 10:49 |
kwharland
Messages: 246
Registered: November 2005
Location: Central Florida
Karma: 0
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Senior Member |
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?
Mr ERFisher wrote on Mon, 16 January 2017 10:19Here is the answer
http://gmc49ers.blogspot.com/2015/09/onan-gmc-propane-conversion.html
Replace the alternator with a simple transformer
I will look for a better link
On Mon, Jan 16, 2017 at 7:11 AM John R. Lebetski
wrote:
> I don't think he went into testing the regulator becsuse that is what is
> being taken out of circuit. The two wires on the "twofer" stay connected
>
> and taped up. Remove spray clean and reseat all the faston terminals as
> they can be oxidized. Also the solders can be bad on the tabs to the board
>
> from vibration. Pull the board and examine the back side with light and
> magnifier. 90% of problems can be found here. Also check fuse tabs solder
> and
>
> clean where the contact fuse. Also be sure fuse is not oversized. Burnt
> traces can be repaired with jumpers if you are good at bench tech basics.
>
> --
>
> John Lebetski
>
> Woodstock, IL
>
> 77 Eleganza II
>
> Source America First
>
>
>
> _______________________________________________
>
> GMCnet mailing list
>
> Unsubscribe or Change List Options:
>
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
>
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1978 Eleganza II
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| Re: Onan starting [message #312153 is a reply to message #312144] |
Mon, 16 January 2017 10:53 |
kwharland
Messages: 246
Registered: November 2005
Location: Central Florida
Karma: 0
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Senior Member |
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Thanks John,
Can the regulator be tested in any way?
I have done the other items you've suggested and found nothing amiss. I'm going to try Matt's suggestions next.
Ken
JohnL455 wrote on Mon, 16 January 2017 10:08I don't think he went into testing the regulator becsuse that is what is being taken out of circuit. The two wires on the "twofer" stay connected and taped up. Remove spray clean and reseat all the faston terminals as they can be oxidized. Also the solders can be bad on the tabs to the board from vibration. Pull the board and examine the back side with light and magnifier. 90% of problems can be found here. Also check fuse tabs solder and clean where the contact fuse. Also be sure fuse is not oversized. Burnt traces can be repaired with jumpers if you are good at bench tech basics.
1978 Eleganza II
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