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| Re: [GMCnet] Bringing Onan back to life due to impending hurricane [message #185526 is a reply to message #185499] |
Sun, 23 September 2012 22:11   |
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mike miller
Messages: 3576
Registered: February 2004
Location: Hillsboro, Oregon
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| Robin Hood wrote on Sun, 23 September 2012 15:45 |
I didn't realize that there was a way to completely bypass the control
board (that does several important things so obviously one should only
bypass for troubleshooting reasons). So how does one bypass the board
completely? I need to see if I can narrow down the cause of my
no-spark condition.
All I've seen so far is that 9to5 runs the pump. But the ignition
system also needs juice.
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There are several ways to jump. Some by-pass more functions than others. I'll explain what is "on" each pin, in order. You may want to look at pins 5 and 9, then go down the list.
Note: Pins 1 to 6 have two pins each, one across the top to connect to the remote and another down lower, mixed in with the rest of the stuff.
Pin 1 is ground for the board. it is also connected to the remote, providing a ground to the remote switch.
Pin 2 is the input to the board for the remote stop function. Grounding this pin cause the board to shut off the generator.
Pin 3 is the input to the board for the remote start function. Grounding this pin cause the board to start the generator.
Pin 4 doesn't seem to be used in our application. Looks like another input into the same circuits that the oil pressure switch connect to.
Pin 5 is FUSED 12 volts from the battery.
Pin 6 has 12volts (fused) only when the generator is running.
Pin 7 is the ground side of the coil of the start solenoid. Grounding this point should cause the starter to engage.
Pin 8 is an A/C "generator running" input to the board from the flywheel alternator. (The other side of this AC signal is pin 5.) It disengages the starter and "latches" the voltage provided to pin 9.
Pin 9 is the output of the board to BOTH the ignition and the fuel pump. If there is voltage here, the pump should be running and the points/coil should have power.
Pin 10 has 12volts from the starter solenoid when the starter is engaged. It provides power to pin 9 when starting.
Pin 11 is UN-FUSED 12 volts from the battery.
Pin 12 is the input of the board from the oil pressure switch. The switch applies a ground when there isn't oil pressure. Just disconnecting this pin disables the function.
NOW for the methods of jumping (bypassing):
The main differences in jumping is where the power comes from, all of them connect to pin 9 (electrically the same point as the + side of the coil, the fuel pump and the fuel shut-off solenoid):
Method 1.) Some jump from pin 11 but it is better to use fused power on pin 5. It pin 11 works but pin 5 does not, look at the fuse.
Method 2.) The most popular spot is pin 5. You still use the button on the board to get the starter to turn. But you need to un-jumper the pins to turn off the generator.
Method 3.) Relatively unknown method is pin 6. This disables the generator running and low oil pressure functions but maintains BOTH the start AND STOP functions of the board. As the lower pin 6 is right next to pin 9, a short one inch jumper can be left in place with the cover on and genset pushed back in the "Onan-hole." Be aware that if you try to start the generator but it doesn't start, there will still be power to the pump and ignition until you press "stop." While all methods keep the power on pin 9, it is just easier to forget without a wire hanging off the generator.
Mike Miller -- Hillsboro, OR -- on the Black list
(#2)`78 23' Birchaven Rear Bath -- (#3)`77 23' Birchaven Side Bath
More Sidekicks than GMC's and a late model Malibu called 'Boo'
http://m000035.blogspot.com
[Updated on: Sun, 23 September 2012 22:13] Report message to a moderator |
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| Re: [GMCnet] Bringing Onan back to life due to impending hurricane [message #187189 is a reply to message #185526] |
Sun, 14 October 2012 08:59 |
Robin Hood
Messages: 1078
Registered: April 2011
Karma: 3
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Back over at Moms messing with the Onan. I've read the manuals and have
them on my kindle for easy access, and this thread. I also have basic tools
and a multimeter.
Is wire "A1-8" on the control board harness important? It doesn't appear to
hook to anything, I see no open terminal points other than number 6.
On Sunday, September 23, 2012, Mike Miller wrote:
>
>
> Robin Hood wrote on Sun, 23 September 2012 15:45
> > I didn't realize that there was a way to completely bypass the control
> > board (that does several important things so obviously one should only
> > bypass for troubleshooting reasons). So how does one bypass the board
> > completely? I need to see if I can narrow down the cause of my
> > no-spark condition.
> >
> > All I've seen so far is that 9to5 runs the pump. But the ignition
> > system also needs juice.
>
>
> There are several ways to jump. Some by-pass more functions than others.
> I'll explain what is "on" each pin, in order. You may want to look at pins
> 5 and 9, then go down the list.
>
> Note: Pins 1 to 6 have two pins each, one across the top to connect to the
> remote and another down lower, mixed in with the rest of the stuff.
>
> Pin 1 is ground for the board. it is also connected to the remote,
> providing a ground to the remote switch.
>
> Pin 2 is the input to the board for the remote stop function.
> Grounding this pin cause the board to shut off the generator.
>
> Pin 3 is the input to the board for the remote start function. Grounding
> this pin cause the board to start the generator.
>
> Pin 4 doesn't seem to be used in our application. Looks like another
> input into the same circuits that the oil pressure switch connect to.
>
> Pin 5 is FUSED 12 volts from the battery.
>
> Pin 6 has 12volts (fused) only when the generator is running.
>
> Pin 7 is the ground side of the coil of the start solenoid. Grounding
> this point should cause the starter to engage.
>
> Pin 8 is an A/C "generator running" input to the board from the flywheel
> alternator. (The other side of this AC signal is pin 5.) It disengages the
> starter and "latches" the voltage provided to pin 9.
>
> Pin 9 is the output of the board to BOTH the ignition and the fuel pump.
> If there is voltage here, the pump should be running and the points/coil
> should have power.
>
> Pin 10 has 12volts from the starter solenoid when the starter is engaged.
> It provides power to pin 9 when starting.
>
> Pin 11 is UN-FUSED 12 volts from the battery.
>
> Pin 12 is the input of the board from the oil pressure switch. The switch
> applies a ground when there isn't oil pressure. Just disconnecting this
> pin disables the function.
>
> NOW for the methods of jumping (bypassing):
>
> The main differences in jumping is where the power comes from, all of them
> connect to pin 9 (electrically the same point as the + side of the coil,
> the fuel pump and the fuel shut-off solenoid):
>
> Method 1.) Some jump from pin 11 but it is better to use fused power on
> pin 5. It pin 11 works but pin 5 does not, look at the fuse.
>
> Method 2.) The most popular spot is pin 5. You still use the button on
> the board to get the starter to turn. But you need to un-jumper the pins
> to turn off the generator.
>
> Method 3.) Relatively unknown method is pin 6. This disables the generator
> running and low oil pressure functions but maintains BOTH the start AND
> STOP functions of the board. As the lower pin 6 is right next to pin 9, a
> short one inch jumper can be left in place with the cover on and genset
> pushed back in the "Onan-hole." Be aware that if you try to start the
> generator but it doesn't start, there will still be power to the pump and
> ignition until you press "stop." While all methods keep the power on pin
> 9, it is just easier to forget without a wire hanging off the generator.
>
>
> --
> Mike Miller -- Hillsboro, OR -- on the Black list
> (#1)'73 26' exPainted D. -- (#2)`78 23' Birchaven Rear Bath -- (#3)`77 23'
> Birchaven Side Bath
> http://m000035.blogspot.com
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
--
Robin Hood
Jackson, MS
2003 Buick Lesabre
1968 Pontiac Catalina
1978 GMC Royale motorhome
1977 GMC Palm Beach motorhome
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| Re: [GMCnet] Bringing Onan back to life due to impending hurricane [message #187195 is a reply to message #187189] |
Sun, 14 October 2012 09:12 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
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Robin,
Pin 8 on the control board receives the signal from the flywheel
alternator. Without that signal (28-31 vac), the board doesn't know the
engine's running and will shut down as soon as you release the starter
switch.
Ken H.
On Sun, Oct 14, 2012 at 9:59 AM, Robin Hood wrote:
...
> Is wire "A1-8" on the control board harness important? It doesn't appear to
> hook to anything, I see no open terminal points other than number 6.
>
>
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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| Re: [GMCnet] Bringing Onan back to life due to impending hurricane [message #187198 is a reply to message #187196] |
Sun, 14 October 2012 09:17 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
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The ignition coil? No. But unless the Start button is pressed, or the
engine's running, it should have 0 VDC.
Ken H.
On Sun, Oct 14, 2012 at 10:15 AM, Robin Hood <loxley@gmail.com> wrote:
> Also on the coil, 8 volts can't be right?
>
> --
> Robin Hood
> Jackson, MS
> 2003 Buick Lesabre
> 1968 Pontiac Catalina
> 1978 GMC Royale motorhome
> 1977 GMC Palm Beach motorhome
> _______________________________________________
> GMCnet mailing list
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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| Re: [GMCnet] Bringing Onan back to life due to impending hurricane [message #187199 is a reply to message #187195] |
Sun, 14 October 2012 09:22 |
Robin Hood
Messages: 1078
Registered: April 2011
Karma: 3
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The wire itself is labeled A1-8. Dies that mean it goes to pin 8?
On Sunday, October 14, 2012, Ken Henderson wrote:
> Robin,
>
> Pin 8 on the control board receives the signal from the flywheel
> alternator. Without that signal (28-31 vac), the board doesn't know the
> engine's running and will shut down as soon as you release the starter
> switch.
>
> Ken H.
>
>
> On Sun, Oct 14, 2012 at 9:59 AM, Robin Hood wrote:
> ...
>
> > Is wire "A1-8" on the control board harness important? It doesn't appear
> to
> > hook to anything, I see no open terminal points other than number 6.
> >
> >
> _______________________________________________
> GMCnet mailing list
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--
Robin Hood
Jackson, MS
2003 Buick Lesabre
1968 Pontiac Catalina
1978 GMC Royale motorhome
1977 GMC Palm Beach motorhome
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| Re: [GMCnet] Bringing Onan back to life due to impending hurricane [message #187207 is a reply to message #187199] |
Sun, 14 October 2012 10:29 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
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It's been a long time since I worked on an Onan, but I can't think of any
other wire that might carry that label -- it IS one of those from the
12-pin connector, isn't it? And has a 3/16" Fast-On flag connector on the
loose end? If so & so, yes, A1-8 goes to pin 8 on the board.
Ken H.
On Sun, Oct 14, 2012 at 10:22 AM, Robin Hood wrote:
> The wire itself is labeled A1-8. Dies that mean it goes to pin 8?
>
> On Sunday, October 14, 2012, Ken Henderson wrote:
>
> > Robin,
> >
> > Pin 8 on the control board receives the signal from the flywheel
> > alternator. Without that signal (28-31 vac), the board doesn't know the
> > engine's running and will shut down as soon as you release the starter
> > switch.
> >
> > Ken H.
> >
> >
> > On Sun, Oct 14, 2012 at 9:59 AM, Robin Hood wrote:
> > ...
> >
> > > Is wire "A1-8" on the control board harness important? It doesn't
> appear
> > to
> > > hook to anything, I see no open terminal points other than number 6.
> > >
> > >
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
> >
>
>
> --
> Robin Hood
> Jackson, MS
> 2003 Buick Lesabre
> 1968 Pontiac Catalina
> 1978 GMC Royale motorhome
> 1977 GMC Palm Beach motorhome
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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| Re: [GMCnet] Bringing Onan back to life due to impending hurricane [message #187212 is a reply to message #187207] |
Sun, 14 October 2012 11:00 |
Robin Hood
Messages: 1078
Registered: April 2011
Karma: 3
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Senior Member |
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Yup, it comes out of the big plastic connector with all the other
wires and has a metal tab on the end of it that could well be
described as flag-like.
I think my little lawn and garden 12v battery may be getting low. I"m
going to come back on another day with a charger/starter to act as a
known good 12v power supply, some contact cleaner, and a video
camera/tripod setup. I could even, in theory, set up some kind of live
streaming video with a laptop, and accept advice from the peanut
gallery, but that's probably more hassle than its worth, although it
might be fun. :)
I'm going to sign up for a gmcphoto account and upload a few pictures.
On Sun, Oct 14, 2012 at 10:29 AM, Ken Henderson <hend4800@bellsouth.net> wrote:
> It's been a long time since I worked on an Onan, but I can't think of any
> other wire that might carry that label -- it IS one of those from the
> 12-pin connector, isn't it? And has a 3/16" Fast-On flag connector on the
> loose end? If so & so, yes, A1-8 goes to pin 8 on the board.
>
> Ken H.
>
> On Sun, Oct 14, 2012 at 10:22 AM, Robin Hood wrote:
>
>> The wire itself is labeled A1-8. Dies that mean it goes to pin 8?
>>
>> On Sunday, October 14, 2012, Ken Henderson wrote:
>>
>> > Robin,
>> >
>> > Pin 8 on the control board receives the signal from the flywheel
>> > alternator. Without that signal (28-31 vac), the board doesn't know the
>> > engine's running and will shut down as soon as you release the starter
>> > switch.
>> >
>> > Ken H.
>> >
>> >
>> > On Sun, Oct 14, 2012 at 9:59 AM, Robin Hood wrote:
>> > ...
>> >
>> > > Is wire "A1-8" on the control board harness important? It doesn't
>> appear
>> > to
>> > > hook to anything, I see no open terminal points other than number 6.
>> > >
>> > >
>> > _______________________________________________
>> > GMCnet mailing list
>> > Unsubscribe or Change List Options:
>> > http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>> >
>>
>>
>> --
>> Robin Hood
>> Jackson, MS
>> 2003 Buick Lesabre
>> 1968 Pontiac Catalina
>> 1978 GMC Royale motorhome
>> 1977 GMC Palm Beach motorhome
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
--
Robin Hood
Jackson, MS
2003 Buick Lesabre
1968 Pontiac Catalina
1978 GMC Royale motorhome
1977 GMC Palm Beach motorhome
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| Re: [GMCnet] Bringing Onan back to life due to impending hurricane [message #187231 is a reply to message #187227] |
Sun, 14 October 2012 15:44 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
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Senior Member |
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I wonder which way that thing's gonna spin when it finally fires off? :-)
You need to get some CRC 2-26 or other good electrical contact cleaner and
wash that board down -- carefully around the switch and the bases of the
relays. Unplug that 12-pin connector, spray it with 2-26 and reconnect it
a few times -- it's a prime problem location.
On the opposite side of the engine from the control board is a finned
voltage regulator, with wires leading toward the ignition coil. There
should be one wire on one terminal and two on the other. Disconnect them
and tape them up -- keep the two together. That's the not-needed regulator
for the Onan-only battery. The A1-12 wire you're tinkering with connects
to that same flywheel alternator; if the regulator fails, nothing works, so
you're eliminating that possibility.
I'd find a way to set the Onan on some substantial wooden shoring before
actually starting it, keeping the engine hoist for suspenders.
Ken H.
On Sun, Oct 14, 2012 at 3:24 PM, Robin Hood wrote:
> http://www.gmcmhphotos.com/photos/g6213-onan-woes.html
>
> I now have a GMCMHPHOTOS.COM account whee! :) Took a minute to figure
> out how to make it go.
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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| Re: [GMCnet] Bringing Onan back to life due to impending hurricane [message #187275 is a reply to message #187231] |
Sun, 14 October 2012 21:16 |
Robin Hood
Messages: 1078
Registered: April 2011
Karma: 3
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Senior Member |
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Yes, the plastic bucket is a field expedient support. I built some GMC
stands that I think will work. Will bring next time.
On Sunday, October 14, 2012, Ken Henderson wrote:
> I wonder which way that thing's gonna spin when it finally fires off? :-)
>
> You need to get some CRC 2-26 or other good electrical contact cleaner and
> wash that board down -- carefully around the switch and the bases of the
> relays. Unplug that 12-pin connector, spray it with 2-26 and reconnect it
> a few times -- it's a prime problem location.
>
> On the opposite side of the engine from the control board is a finned
> voltage regulator, with wires leading toward the ignition coil. There
> should be one wire on one terminal and two on the other. Disconnect them
> and tape them up -- keep the two together. That's the not-needed regulator
> for the Onan-only battery. The A1-12 wire you're tinkering with connects
> to that same flywheel alternator; if the regulator fails, nothing works, so
> you're eliminating that possibility.
>
> I'd find a way to set the Onan on some substantial wooden shoring before
> actually starting it, keeping the engine hoist for suspenders.
>
> Ken H.
>
> On Sun, Oct 14, 2012 at 3:24 PM, Robin Hood wrote:
>
> > http://www.gmcmhphotos.com/photos/g6213-onan-woes.html
> >
> > I now have a GMCMHPHOTOS.COM account whee! :) Took a minute to figure
> > out how to make it go.
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
--
Robin Hood
Jackson, MS
2003 Buick Lesabre
1968 Pontiac Catalina
1978 GMC Royale motorhome
1977 GMC Palm Beach motorhome
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