| [GMCnet] AAaargh. The Onan. Again. Intermittent spark [message #280427] |
Sun, 21 June 2015 09:15  |
glwgmc
Messages: 1014
Registered: June 2004
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Check your coil for correct polarity. On our Royale, the coil was installed backward. Positive should be to the back of the Onan. The Gary Bovee Pertronics kit will solve a lot of points related issues and it is really simple to install.
Jerry
Jerry Work
The Dovetail Joint
Fine furniture designed & hand crafted
in the 1907 former Masonic Temple building
in historic Kerby, OR
http://jerrywork.com
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78 Royale
Kerby, OR
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| Re: [GMCnet] AAaargh. The Onan. Again. Intermittent spark [message #280430 is a reply to message #280427] |
Sun, 21 June 2015 10:07  |
Otterwan
Messages: 946
Registered: July 2013
Location: Lynnwood (north of Seattl...
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glwgmc wrote on Sun, 21 June 2015 07:15Check your coil for correct polarity. On our Royale, the coil was installed backward. Positive should be to the back of the Onan. The Gary Bovee Pertronics kit will solve a lot of points related issues and it is really simple to install.
Jerry
Thanks Jerry, already did that. Negative goes to the points (and nothing else); power, condenser, and fuel pump power goes to the positive. I'm starting to wonder if the condenser on the coil is bad. I think I have another to try.
1977 Birchaven, Lynnwood WA - "We may not be able to stop all evil in the world, but I know that how we treat one another is entirely up to us."
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| Re: [GMCnet] AAaargh. The Onan. Again. Intermittent spark [message #280451 is a reply to message #280430] |
Sun, 21 June 2015 15:03 |
Daniel Starks
Messages: 20
Registered: April 2015
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I thought the condenser went to same terminal as the points, you might
check the manual.
Daniel
-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of
David Orders
Sent: Sunday, June 21, 2015 9:08 AM
To: gmclist@temp.gmcnet.org
Subject: Re: [GMCnet] AAaargh. The Onan. Again. Intermittent spark
glwgmc wrote on Sun, 21 June 2015 07:15
> Check your coil for correct polarity. On our Royale, the coil was
> installed backward. Positive should be to the back of the Onan. The
Gary Bovee Pertronics kit will solve a lot of points related issues and
it is really simple to install.
>
> Jerry
Thanks Jerry, already did that. Negative goes to the points (and nothing
else); power, condenser, and fuel pump power goes to the positive. I'm
starting to wonder if the condenser on the coil is bad. I think I have
another to try.
--
1976 Royale "Twinkie II" Lynnwood WA - "We may not be able to stop all
evil in the world, but I know that how we treat one another is entirely
up to us."
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| Re: [GMCnet] AAaargh. The Onan. Again. Intermittent spark [message #280473 is a reply to message #280451] |
Mon, 22 June 2015 08:10 |
Jim Miller
Messages: 501
Registered: March 2008
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> On Jun 21, 2015, at 4:03 PM, Daniel Starks wrote:
>
> I thought the condenser went to same terminal as the points, you might check the manual.
The coil-mounted condenser goes to the + terminal as shown in the schematics on page 53 of the service manual. Its designator is C2.
The breaker point condenser OTOH is shown as an integral part of the “breaker point and cap" assembly S1.
Anyone having ignition problems should absolutely consider the condensers as a source of problems - they are devices that have a high probability of failure and this probability increases based on age and exposure to temperature extremes. I repair a lot of electronic equipment and I always give capacitors (condensers) top priority in the troubleshooting process since they are so often the cause of the problem. They fail in many insidious ways including becoming complete shorts or complete opens (minimal or no capacitance at all) as well as their series resistance reaching problematic levels. In some cases their (mis)behavior changes based on operating temperature so testing them on the bench gives one result while in circuit they start doing something different. Replace them if in doubt - they are inexpensive!
--Jim "saving the lives of Onans...one unit at a time" Miller
1977 Eleganza II
1977 Royale
Hamilton, OH
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Jim Miller
1977 Eleganza II
1977 Royale
Hamilton, OH
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| Re: [GMCnet] AAaargh. The Onan. Again. Intermittent spark [message #280495 is a reply to message #280427] |
Mon, 22 June 2015 14:33 |
Otterwan
Messages: 946
Registered: July 2013
Location: Lynnwood (north of Seattl...
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OK, cleaned, adjusted, replaced, and checked about everything. Now if I jumper 12 volt straight from the starter to coil + and hit the switch it fires right up and runs great. So what is going on here, the control board? Without the jumper I'm measuring 10.45 volts at the positive coil terminal when cranking. I'm totally confused.
1977 Birchaven, Lynnwood WA - "We may not be able to stop all evil in the world, but I know that how we treat one another is entirely up to us."
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| Re: [GMCnet] AAaargh. The Onan. Again. Intermittent spark [message #280504 is a reply to message #280427] |
Mon, 22 June 2015 15:21 |
jhbridges
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
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The board, or its associated wiring. I'd look first for corrosion/looseness/green grot on the blade connectors where the wire crimps in them, and where the wires crimp into the Molex<tm> pins and sockets where the board harness connects to the genset wiring. I'd also look at the term of each wire on the genset for a crummy connection.
NOTE: While the pins and sockets can be removed from the connector using a standard tool, they are NOT either of the standard sizes. If you find a problem in one or more, buy a current Molex 12 pin plug and socket and a set of standard size pins. New stranded wire, replace one at a time end to plug to other end. Check the card... looking especially for cracks where the blades are crimped and soldered to the board.
--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: [GMCnet] AAaargh. The Onan. Again. Intermittent spark [message #280510 is a reply to message #280427] |
Mon, 22 June 2015 15:47 |
jhbridges
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
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Suggestions still apply. You're describing a crummy connection someplace, unless the Dino boards use something other than a simple relay contact to keep the thing going. (I've never seen the Dinosaur board, only pictures. I can usually fix the originals.) I assume the board you have used the old Molex connector and pigtail coming from the genset? Look at those first if you still have 40 Y/O wires and connectors. And for a quick n dirty, pull the oil pressure sensor wire off if you haven't already and see of that helps. Sensors die, and oldsters lose pressure.
--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: [GMCnet] AAaargh. The Onan. Again. Intermittent spark [message #280515 is a reply to message #280510] |
Mon, 22 June 2015 17:05 |
Mike Kilroy
Messages: 80
Registered: July 2006
Location: Farmersville, OH (near D...
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----- Original Message -----
From: "Johnny Bridges"
To: gmclist@temp.gmcnet.org
Sent: Monday, June 22, 2015 4:47:27 PM
Subject: Re: [GMCnet] AAaargh. The Onan. Again. Intermittent spark
Suggestions still apply. You're describing a crummy connection someplace, unless the Dino boards use something other than a simple relay contact to
keep the thing going. (I've never seen the Dinosaur board, only pictures. I can usually fix the originals.) I assume the board you have used the
old Molex connector and pigtail coming from the genset? Look at those first if you still have 40 Y/O wires and connectors. And for a quick n dirty,
pull the oil pressure sensor wire off if you haven't already and see of that helps. Sensors die, and oldsters lose pressure.
--johnny
--
'76 23' transmode Norris upfit
Braselton, Ga.
"Sometimes I wonder what tomorrow's gonna bring when I think about my dirty life and times" --Warren Zevon
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Mike (AC8V) & Vickie Kilroy
'73 Canyon Land 26' sidebath
455/ceramic filled crossovers
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| Re: [GMCnet] AAaargh. The Onan. Again. Intermittent spark [message #280600 is a reply to message #280598] |
Tue, 23 June 2015 23:35 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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Our Dino boards come two ways; one for the pre 75 has the pins the 76-78 we
supply the one with the pigtail with connector and is a fast and easy
switch.
On Tue, Jun 23, 2015 at 8:23 PM, Brian Waddell
wrote:
> what is the difference if any between condenser on onan and the one or
> heater fan. thx...brian 77 ele 455
>
>
>> From: gmcnet@jcmco.com
>> Date: Mon, 22 Jun 2015 09:10:37 -0400
>> To: gmclist@temp.gmcnet.org
>> Subject: Re: [GMCnet] AAaargh. The Onan. Again. Intermittent spark
>>
>>> On Jun 21, 2015, at 4:03 PM, Daniel Starks
> wrote:
>>>
>>> I thought the condenser went to same terminal as the points, you might
> check the manual.
>>
>> The coil-mounted condenser goes to the + terminal as shown in the
> schematics on page 53 of the service manual. Its designator is C2.
>>
>> The breaker point condenser OTOH is shown as an integral part of the
> “breaker point and cap" assembly S1.
>>
>> Anyone having ignition problems should absolutely consider the
> condensers as a source of problems - they are devices that have a high
> probability of failure and this probability increases based on age and
> exposure to temperature extremes. I repair a lot of electronic equipment
> and I always give capacitors (condensers) top priority in the
> troubleshooting process since they are so often the cause of the problem.
> They fail in many insidious ways including becoming complete shorts or
> complete opens (minimal or no capacitance at all) as well as their series
> resistance reaching problematic levels. In some cases their (mis)behavior
> changes based on operating temperature so testing them on the bench gives
> one result while in circuit they start doing something different. Replace
> them if in doubt - they are inexpensive!
>>
>> --Jim "saving the lives of Onans...one unit at a time" Miller
>> 1977 Eleganza II
>> 1977 Royale
>> Hamilton, OH
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
> _______________________________________________
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--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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www.appliedgmc.com
1-800-752-7502
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| Re: [GMCnet] AAaargh. The Onan. Again. Intermittent spark [message #280604 is a reply to message #280598] |
Wed, 24 June 2015 04:13 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Condensers (capacitors) are use for two things. There is one wired across the points that is used of arc suppression to keep from or reduce the amount of points burning. It is used on all points type ignitions.
The second use for a capacitor / condenser is for radio noise suppression. You will find these on the positive side of heater fan and ignition coils on both Onan and engine. Unlike the ignition capacitors, you can get by with out these and the engines will run fine.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: [GMCnet] AAaargh. The Onan. Again. Intermittent spark [message #280751 is a reply to message #280427] |
Fri, 26 June 2015 03:49 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Capacitors are measured in micro-farads abbreviated mfd.
This is what I remember and it could be faulty. The capacity of a points ignition capacitor ranges from 0.2 micro-farad to 0.33 micro-farad. The value varies by the coil used and most automotive coils used around .25 to .30 mfd.
Noise suppression capacitors are usually .5 to 1.0 mfd. If they go bad nothing serious happens you just hear noise in your radio. I have seen some of these that had their value stamped on the outside of the case.
On the ignition side, I would not reuse an old capacitor. They tend to degrade over time. Choose a new capacitor that matches your exact coil and points set up.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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