Onan

[hermann beeck]

Scott
Is this what you'r looking for?
http://www.gmcws.org/Tech/dsimmons/onan/onan.html

- -----Original Message-----
From: Adohen
Sent: Mon, 12 Jun 2000 02:41:05 EDT
To: gmcmotorhome
Subject: GMC: Onan

Does any one have the seminar handout Duane Simmons presented copied on a=
=20
website? I've looked but can't find it.=20
Thanks

Scott =20

_________________________________________________________________________=
__
Visit http://www.visto.com/info, your free web-based communications cente=
r.
Visto.com. Life on the Dot.

 

[bdub]

My Onan will start and run as long as I have the Jim Bounds Priming Button
pushed. When I let it go, the onan dies. Would this be typical of a bad
oil pressure switch? It was a quart low on oil, but upon adding the
missing quart, it still won't continue to run.

Any suggestions?

Thanks
bdub

 

[emerystora]

>My Onan will start and run as long as I have the Jim Bounds Priming
>Button pushed. When I let it go, the onan dies. Would this be
>typical of a bad oil pressure switch? It was a quart low on oil,
>but upon adding the missing quart, it still won't continue to run.
>
>Any suggestions?
>
>Thanks
>bdub

Billy -- when the primer switch is pressed it bypasses the low oil
pressure switch but also applies current to the fuel pump. It could
be a low oil pressure switch but you can easily put a jumper across
that switch and eliminate it to see if the Onan then runs. It could
also be a circuit on the board or bad connections on the board. Try
cleaning all the connectors with some contact cleaner and see if it
helps. If not, you'll probably need board repair. I had a similar
problem several years ago and noticed some powdery residue by a
couple of the electrolytic capacitors. I replaced the capacitors
with the closest value ones I could buy at Radio Shack and it cured
the problem. One of the relays was not closing properly and the
capacitor was in that circuit.

You might want Duane Simmons to give you his suggestions as he is
very familar with the operation of the control board and has given
seminars on it.

Emery Stora
77 Kingsley
Santa Fe, NM

 

[bdub]

Thanks Emery

I can power the coil from the battery (which also powers the fuel pump) and
it starts right up. As soon as I take the jumper off, the onan dies.

The unit ran all weekend just fine. It died a couple of times on the way
back from Austin and finally wouldn't start any more. Like whatever went
wrong, happened over several hours before it totally failed. I definitely
want to hear what Duane's got to say about it. If anyone will know, he will.

Thanks again
bdub

>>My Onan will start and run as long as I have the Jim Bounds Priming
>>Button pushed. When I let it go, the onan dies. Would this be typical
>>of a bad oil pressure switch? It was a quart low on oil, but upon adding
>>the missing quart, it still won't continue to run.
>>
>>Any suggestions?
>>
>>Thanks
>>bdub
>
>Billy -- when the primer switch is pressed it bypasses the low oil
>pressure switch but also applies current to the fuel pump. It could be a
>low oil pressure switch but you can easily put a jumper across that switch
>and eliminate it to see if the Onan then runs. It could also be a circuit
>on the board or bad connections on the board. Try cleaning all the
>connectors with some contact cleaner and see if it helps. If not, you'll
>probably need board repair. I had a similar problem several years ago and
>noticed some powdery residue by a couple of the electrolytic
>capacitors. I replaced the capacitors with the closest value ones I could
>buy at Radio Shack and it cured the problem. One of the relays was not
>closing properly and the capacitor was in that circuit.
>
>You might want Duane Simmons to give you his suggestions as he is very
>familar with the operation of the control board and has given seminars on it.
>
>Emery Stora
>77 Kingsley
>Santa Fe, NM

 

[bdub]

Thanks Tom

I looked over all the wires and cleaned up all the terminals. Everything
"looks" normal. I'll check voltage, but am not real sure where to check it at.

bdub

>The answer is you have a bad DC feed to the onan. Probably the wire is
>frayed or pinched someplacecausing a large voltage drop. Check the voltage
>at the terminal with a voltmeter.
>
>

> >Thanks Emery
> >
> >I can power the coil from the battery (which also powers the fuel pump) and
> >it starts right up. As soon as I take the jumper off, the onan dies.
> >
> >The unit ran all weekend just fine. It died a couple of times on the way
> >back from Austin and finally wouldn't start any more. Like whatever went
> >wrong, happened over several hours before it totally failed. I definitely
> >want to hear what Duane's got to say about it. If anyone will know, he
> will.
> >
> >Thanks again
> >bdub
> >
> >

> >>>My Onan will start and run as long as I have the Jim Bounds Priming
> >>>Button pushed. When I let it go, the onan dies. Would this be typical
> >>>of a bad oil pressure switch? It was a quart low on oil, but upon adding
> >>>the missing quart, it still won't continue to run.
> >>>
> >>>Any suggestions?
> >>>
> >>>Thanks
> >>>bdub
> >>
> >>Billy -- when the primer switch is pressed it bypasses the low oil
> >>pressure switch but also applies current to the fuel pump. It could be a
> >>low oil pressure switch but you can easily put a jumper across that switch
> >>and eliminate it to see if the Onan then runs. It could also be a circuit
> >>on the board or bad connections on the board. Try cleaning all the
> >>connectors with some contact cleaner and see if it helps. If not, you'll
> >>probably need board repair. I had a similar problem several years ago and
> >>noticed some powdery residue by a couple of the electrolytic
> >>capacitors. I replaced the capacitors with the closest value ones I could
> >>buy at Radio Shack and it cured the problem. One of the relays was not
> >>closing properly and the capacitor was in that circuit.
> >>
> >>You might want Duane Simmons to give you his suggestions as he is very
> >>familar with the operation of the control board and has given seminars
> on it.
> >>
> >>Emery Stora
> >>77 Kingsley
> >>Santa Fe, NM
> >
> >
> >

 

[gene]

It sounds more like a control board / relay problem... Sounds like lyou are
not getting power to the fuel pump ??

gene

>My Onan will start and run as long as I have the Jim Bounds Priming Button
>pushed. When I let it go, the onan dies. Would this be typical of a bad
>oil pressure switch? It was a quart low on oil, but upon adding the
>missing quart, it still won't continue to run.
>
>Any suggestions?
>
>Thanks
>bdub
>
>
gene fisher 76 PB/OR/CA
GMC MOTORHOME INFORMATION
mr.erf
http://www.california.com/~eagle/

 

[bdub]

Thanks Tom

I've got 12.62 vdc at the battery and every terminal on the onan that'll
show power. If it's a frayed wire, it's completely broken now.

bdub

>check it right at the coil and compare it to the battery voltage. I have not
>got my wiring diagrams here for it, but the wire must be color coded. Trace
>it back if the voltage is low at the coil and repair the wire.
>
>

> >Thanks Tom
> >
> >I looked over all the wires and cleaned up all the terminals. Everything
> >"looks" normal. I'll check voltage, but am not real sure where to check
> it at.
> >
> >bdub
> >
> >

> >>The answer is you have a bad DC feed to the onan. Probably the wire is
> >>frayed or pinched someplacecausing a large voltage drop. Check the voltage
> >>at the terminal with a voltmeter.
> >>
> >>

> >> >Thanks Emery
> >> >
> >> >I can power the coil from the battery (which also powers the fuel
> pump) and
> >> >it starts right up. As soon as I take the jumper off, the onan dies.
> >> >
> >> >The unit ran all weekend just fine. It died a couple of times on the way
> >> >back from Austin and finally wouldn't start any more. Like whatever went
> >> >wrong, happened over several hours before it totally failed. I
> definitely
> >> >want to hear what Duane's got to say about it. If anyone will know, he
> >> will.
> >> >
> >> >Thanks again
> >> >bdub
> >> >
> >> >

> >> >>>My Onan will start and run as long as I have the Jim Bounds Priming
> >> >>>Button pushed. When I let it go, the onan dies. Would this be typical
> >> >>>of a bad oil pressure switch? It was a quart low on oil, but upon
> adding
> >> >>>the missing quart, it still won't continue to run.
> >> >>>
> >> >>>Any suggestions?
> >> >>>
> >> >>>Thanks
> >> >>>bdub
> >> >>
> >> >>Billy -- when the primer switch is pressed it bypasses the low oil
> >> >>pressure switch but also applies current to the fuel pump. It could
> be a
> >> >>low oil pressure switch but you can easily put a jumper across that
> switch
> >> >>and eliminate it to see if the Onan then runs. It could also be a
> circuit
> >> >>on the board or bad connections on the board. Try cleaning all the
> >> >>connectors with some contact cleaner and see if it helps. If not,
> you'll
> >> >>probably need board repair. I had a similar problem several years
> ago and
> >> >>noticed some powdery residue by a couple of the electrolytic
> >> >>capacitors. I replaced the capacitors with the closest value ones I
> could
> >> >>buy at Radio Shack and it cured the problem. One of the relays was not
> >> >>closing properly and the capacitor was in that circuit.
> >> >>
> >> >>You might want Duane Simmons to give you his suggestions as he is very
> >> >>familar with the operation of the control board and has given seminars
> >> on it.
> >> >>
> >> >>Emery Stora
> >> >>77 Kingsley
> >> >>Santa Fe, NM
> >> >
> >> >
> >> >
> >
> >
> >

 

[bdub]

http://www.gmcws.org/Tech/dsimmons/onan/onan.html

If I understand this booklet correctly, the voltage path to the coil and
fuel pump and choke is supposed to be furnished by the start switch until
the onan produces 10 volts or so AC which energizes a relay that then takes
over this job when the switch is released.

It seems that for some reason, the switch, although it still actuates the
starter, has quit powering the coil and pump. The relay latches when the
onan is up to speed with the jumper on, (I took the cover off and watched
it) but as soon as I take the jumper off, it dies. Jumper from #5 to #9 or
from the battery to the + coil does the same thing.

Another thing that might have something to do with it is that the starter
will, once in a great while, hang and not disengage when the onan
starts. I have to run around and open the hatch and hit the start button a
few times until it finally disengages. This has happened 3 or 4 times. Of
course it doesn't happen any more unless I have that jumper wire installed.

It's all very confusing to me. I hope to get some of the resident
Classic's experts to take a look at it tomorrow at the rally.

Thanks for the effort. I'm just a little slow, I think.
bdub

>Guess I dont understand billy.you also have 12.6VDC at the coil to? If so I
>cant understand why it wont start without the assistane of a jump to that
>terminal UNLESS the fuel pump is drawing so much current that it drops the
>voltage beyond where is will start.Put the voltmeter on the coil terminal
>and crank the onan and see how much the voltage drops.
>
>

> >Thanks Tom
> >
> >I've got 12.62 vdc at the battery and every terminal on the onan that'll
> >show power. If it's a frayed wire, it's completely broken now.
> >
> >bdub
> >
> >
> >
> >
> >

> >>check it right at the coil and compare it to the battery voltage. I
> have not
> >>got my wiring diagrams here for it, but the wire must be color coded. Trace
> >>it back if the voltage is low at the coil and repair the wire.
> >>
> >>

> >> >Thanks Tom
> >> >
> >> >I looked over all the wires and cleaned up all the terminals. Everything
> >> >"looks" normal. I'll check voltage, but am not real sure where to check
> >> it at.
> >> >
> >> >bdub
> >> >
> >> >

> >> >>The answer is you have a bad DC feed to the onan. Probably the wire is
> >> >>frayed or pinched someplacecausing a large voltage drop. Check the
> voltage
> >> >>at the terminal with a voltmeter.
> >> >>
> >> >>

> >> >> >Thanks Emery
> >> >> >
> >> >> >I can power the coil from the battery (which also powers the fuel
> >> pump) and
> >> >> >it starts right up. As soon as I take the jumper off, the onan dies.
> >> >> >
> >> >> >The unit ran all weekend just fine. It died a couple of times on
> the way
> >> >> >back from Austin and finally wouldn't start any more. Like
> whatever went
> >> >> >wrong, happened over several hours before it totally failed. I
> >> definitely
> >> >> >want to hear what Duane's got to say about it. If anyone will
> know, he
> >> >> will.
> >> >> >
> >> >> >Thanks again
> >> >> >bdub
> >> >> >
> >> >> >

> >> >> >>>My Onan will start and run as long as I have the Jim Bounds Priming
> >> >> >>>Button pushed. When I let it go, the onan dies. Would this be
> typical
> >> >> >>>of a bad oil pressure switch? It was a quart low on oil, but upon
> >> adding
> >> >> >>>the missing quart, it still won't continue to run.
> >> >> >>>
> >> >> >>>Any suggestions?
> >> >> >>>
> >> >> >>>Thanks
> >> >> >>>bdub
> >> >> >>
> >> >> >>Billy -- when the primer switch is pressed it bypasses the low oil
> >> >> >>pressure switch but also applies current to the fuel pump. It could
> >> be a
> >> >> >>low oil pressure switch but you can easily put a jumper across that
> >> switch
> >> >> >>and eliminate it to see if the Onan then runs. It could also be a
> >> circuit
> >> >> >>on the board or bad connections on the board. Try cleaning all the
> >> >> >>connectors with some contact cleaner and see if it helps. If not,
> >> you'll
> >> >> >>probably need board repair. I had a similar problem several years
> >> ago and
> >> >> >>noticed some powdery residue by a couple of the electrolytic
> >> >> >>capacitors. I replaced the capacitors with the closest value ones I
> >> could
> >> >> >>buy at Radio Shack and it cured the problem. One of the relays
> was not
> >> >> >>closing properly and the capacitor was in that circuit.
> >> >> >>
> >> >> >>You might want Duane Simmons to give you his suggestions as he is
> very
> >> >> >>familar with the operation of the control board and has given
> seminars
> >> >> on it.
> >> >> >>
> >> >> >>Emery Stora
> >> >> >>77 Kingsley
> >> >> >>Santa Fe, NM
> >> >> >
> >> >> >
> >> >> >
> >> >
> >> >
> >> >
> >
> >
> >

 

[tim dawson]

If you remove the cover form the relay that powers the fuel pump, etc (the one
with the single two pole contact) and push it in with your finger, do you
hear the fuel pump run? If you crank the unit and do this, will it start and
stay running? If so, I may have your solution - I just fixed a card for this
problem for another netter. The voltage to that relay is dropped via a
resistor, and it gets much less than 12 volts. If the cover has been pulled
off the relay "carelesslt" (Can't come up with a better word . . .) the relay
pole piece and spring can get pulled up away from the armature, so that the
magnetic gap is much greater than it sould normally be, and there is not
enough voltage to pull it in. (The other netter with this problem could start
fine when plugged into shore power, but not from battery - the go/no go line
on this is that sharp). To check this, look at the relay movable contact
piece at the end opposite the contacts. If it is not sitting down as close to
the relay coil/battery as it can, then gently adjust the spring at the rear of
the relay until it does - the gap on this relay is typically 1/16" or so
when set correctly.

If the tests above do not reveal that you have this problem, then others may
want to keep this in mind, since it appears to be a pretty easy situation to
get into - I inadvertently did it to mine (and found/fixed it . .) and have
dealt with the problem for one other person . .

- - Tim

> Thanks Emery
>
> I can power the coil from the battery (which also powers the fuel pump) and
> it starts right up. As soon as I take the jumper off, the onan dies.
>
> The unit ran all weekend just fine. It died a couple of times on the way
> back from Austin and finally wouldn't start any more. Like whatever went
> wrong, happened over several hours before it totally failed. I definitely
> want to hear what Duane's got to say about it. If anyone will know, he will.
>
> Thanks again
> bdub
>
>

> >>My Onan will start and run as long as I have the Jim Bounds Priming
> >>Button pushed. When I let it go, the onan dies. Would this be typical
> >>of a bad oil pressure switch? It was a quart low on oil, but upon adding
> >>the missing quart, it still won't continue to run.
> >>
> >>Any suggestions?
> >>
> >>Thanks
> >>bdub
> >
> >Billy -- when the primer switch is pressed it bypasses the low oil
> >pressure switch but also applies current to the fuel pump. It could be a
> >low oil pressure switch but you can easily put a jumper across that switch
> >and eliminate it to see if the Onan then runs. It could also be a circuit
> >on the board or bad connections on the board. Try cleaning all the
> >connectors with some contact cleaner and see if it helps. If not, you'll
> >probably need board repair. I had a similar problem several years ago and
> >noticed some powdery residue by a couple of the electrolytic
> >capacitors. I replaced the capacitors with the closest value ones I could
> >buy at Radio Shack and it cured the problem. One of the relays was not
> >closing properly and the capacitor was in that circuit.
> >
> >You might want Duane Simmons to give you his suggestions as he is very
> >familar with the operation of the control board and has given seminars on it.
> >
> >Emery Stora
> >77 Kingsley
> >Santa Fe, NM
>
>

- --
================================================================================
Tim Dawson (tadawson) Owner/Engineer
TPC Services Bellnet: (972)-221-7385
Lewisville, Texas 75067 FAXnet: (972)-221-0393
"The world is complex. Sendmail.cf reflects this...."

 

[bdub]

Thanks Tim

I think I might've fixed the problem today. I took the board off and found
that the upper right hand terminal of the K3 relay's solder joint had
broken. I also found where the solder trace to the top #5 terminal was
making intermittent contact because of corrosion. I repaired these two
places, resealed the board and remounted it.

When I hit the start switch, I noticed that the choke now moves. I don't
think that was happening before.

Anyway, I parked the coach yesterday with the reserve fuel tank switch
on. I wanted it to be nearly dry because I was thinking about dropping the
tanks and re-doing all the hoses and vents. Of course, the Onan wouldn't
start because it wasn't getting any fuel. Went and got a can of gas and
rigged up a temp fuel line for it. Then, before it started, the dern
starter fouled up on me. I took it off and the armature moves about a
1/16" in the wore out bushing. So I guess I've got to fix that before I
can see if the board works.

I cleaned up the tools and shoved the Onan back into it's drawer but the
door wouldn't shut. I pulled it back out and looked behind it to see what
was making it not go in far enough but didn't see anything. I shoved it
really hard to try to make it go in enough. It didn't. Got to looking and
found the starter bracket was catching on the bottom of the
compartment. It's broken and hanging down too low. Now I bent the crap
out of it. Guess I've got another item to order from Golby's.

I was thinking, while I tore the sheet metal and flywheel off the Onan,
about how appropriate GMC domino's really are. It seems that any time I
work on the GMC, there's something else that needs to be fixed too, and
then on and on, like a domino effect.

Thanks for the suggestion. I saw that little relay shutting when I pushed
the starter button. Will keep it in mind when ever I get back to that point.

Does anyone know a good source for Onan starter bushings besides Onan?

Thanks
bdub

>If you remove the cover form the relay that powers the fuel pump, etc (the one
>with the single two pole contact) and push it in with your finger, do you
>hear the fuel pump run? If you crank the unit and do this, will it start and
>stay running? If so, I may have your solution - I just fixed a card for this
>problem for another netter. The voltage to that relay is dropped via a
>resistor, and it gets much less than 12 volts. If the cover has been pulled
>off the relay "carelesslt" (Can't come up with a better word . . .) the relay
>pole piece and spring can get pulled up away from the armature, so that the
>magnetic gap is much greater than it sould normally be, and there is not
>enough voltage to pull it in. (The other netter with this problem could start
>fine when plugged into shore power, but not from battery - the go/no go line
>on this is that sharp). To check this, look at the relay movable contact
>piece at the end opposite the contacts. If it is not sitting down as
>close to
>the relay coil/battery as it can, then gently adjust the spring at the rear of
>the relay until it does - the gap on this relay is typically 1/16" or so
>when set correctly.
>
>If the tests above do not reveal that you have this problem, then others may
>want to keep this in mind, since it appears to be a pretty easy situation to
>get into - I inadvertently did it to mine (and found/fixed it . .) and have
>dealt with the problem for one other person . .
>
>- Tim
>
> > Thanks Emery
> >
> > I can power the coil from the battery (which also powers the fuel pump)
> and
> > it starts right up. As soon as I take the jumper off, the onan dies.
> >
> > The unit ran all weekend just fine. It died a couple of times on the way
> > back from Austin and finally wouldn't start any more. Like whatever went
> > wrong, happened over several hours before it totally failed. I definitely
> > want to hear what Duane's got to say about it. If anyone will know, he
> will.
> >
> > Thanks again
> > bdub
> >
> >

> > >>My Onan will start and run as long as I have the Jim Bounds Priming
> > >>Button pushed. When I let it go, the onan dies. Would this be typical
> > >>of a bad oil pressure switch? It was a quart low on oil, but upon
> adding
> > >>the missing quart, it still won't continue to run.
> > >>
> > >>Any suggestions?
> > >>
> > >>Thanks
> > >>bdub
> > >
> > >Billy -- when the primer switch is pressed it bypasses the low oil
> > >pressure switch but also applies current to the fuel pump. It could be a
> > >low oil pressure switch but you can easily put a jumper across that
> switch
> > >and eliminate it to see if the Onan then runs. It could also be a
> circuit
> > >on the board or bad connections on the board. Try cleaning all the
> > >connectors with some contact cleaner and see if it helps. If not, you'll
> > >probably need board repair. I had a similar problem several years ago
> and
> > >noticed some powdery residue by a couple of the electrolytic
> > >capacitors. I replaced the capacitors with the closest value ones I
> could
> > >buy at Radio Shack and it cured the problem. One of the relays was not
> > >closing properly and the capacitor was in that circuit.
> > >
> > >You might want Duane Simmons to give you his suggestions as he is very
> > >familar with the operation of the control board and has given seminars
> on it.
> > >
> > >Emery Stora
> > >77 Kingsley
> > >Santa Fe, NM
> >
> >
>
>
>--
>================================================================================
>Tim Dawson (tadawson) Owner/Engineer
>TPC Services Bellnet: (972)-221-7385
>Lewisville, Texas 75067 FAXnet: (972)-221-0393
>"The world is complex. Sendmail.cf reflects this...."

 

[gene]

John Bush found that often the starter bracket is broken because the rubber
motor mounts on the Onan are bad and let the starter rest on the pan..... so
you might want to replace these mounts also.

on my web page, Duane suggests it might cost almost as much to rebuild the
starter as buy a new one and that the Onan number (he gives it) has changed.

gene

>Thanks Tim
>
>I think I might've fixed the problem today. I took the board off and found
>that the upper right hand terminal of the K3 relay's solder joint had
>broken. I also found where the solder trace to the top #5 terminal was
>making intermittent contact because of corrosion. I repaired these two
>places, resealed the board and remounted it.
>
>When I hit the start switch, I noticed that the choke now moves. I don't
>think that was happening before.
>
>Anyway, I parked the coach yesterday with the reserve fuel tank switch
>on. I wanted it to be nearly dry because I was thinking about dropping the
>tanks and re-doing all the hoses and vents. Of course, the Onan wouldn't
>start because it wasn't getting any fuel. Went and got a can of gas and
>rigged up a temp fuel line for it. Then, before it started, the dern
>starter fouled up on me. I took it off and the armature moves about a
>1/16" in the wore out bushing. So I guess I've got to fix that before I
>can see if the board works.
>
>I cleaned up the tools and shoved the Onan back into it's drawer but the
>door wouldn't shut. I pulled it back out and looked behind it to see what
>was making it not go in far enough but didn't see anything. I shoved it
>really hard to try to make it go in enough. It didn't. Got to looking and
>found the starter bracket was catching on the bottom of the
>compartment. It's broken and hanging down too low. Now I bent the crap
>out of it. Guess I've got another item to order from Golby's.
>
>I was thinking, while I tore the sheet metal and flywheel off the Onan,
>about how appropriate GMC domino's really are. It seems that any time I
>work on the GMC, there's something else that needs to be fixed too, and
>then on and on, like a domino effect.
>
>Thanks for the suggestion. I saw that little relay shutting when I pushed
>the starter button. Will keep it in mind when ever I get back to that point.
>
>Does anyone know a good source for Onan starter bushings besides Onan?
>
>Thanks
>bdub
>
>
>
>

>>If you remove the cover form the relay that powers the fuel pump, etc
(the one
>>with the single two pole contact) and push it in with your finger, do you
>>hear the fuel pump run? If you crank the unit and do this, will it start
and
>>stay running? If so, I may have your solution - I just fixed a card for
this
>>problem for another netter. The voltage to that relay is dropped via a
>>resistor, and it gets much less than 12 volts. If the cover has been pulled
>>off the relay "carelesslt" (Can't come up with a better word . . .) the
relay
>>pole piece and spring can get pulled up away from the armature, so that the
>>magnetic gap is much greater than it sould normally be, and there is not
>>enough voltage to pull it in. (The other netter with this problem could
start
>>fine when plugged into shore power, but not from battery - the go/no go line
>>on this is that sharp). To check this, look at the relay movable contact
>>piece at the end opposite the contacts. If it is not sitting down as
>>close to
>>the relay coil/battery as it can, then gently adjust the spring at the
rear of
>>the relay until it does - the gap on this relay is typically 1/16" or so
>>when set correctly.
>>
>>If the tests above do not reveal that you have this problem, then others may
>>want to keep this in mind, since it appears to be a pretty easy situation to
>>get into - I inadvertently did it to mine (and found/fixed it . .) and have
>>dealt with the problem for one other person . .
>>
>>- Tim
>>
>> > Thanks Emery
>> >
>> > I can power the coil from the battery (which also powers the fuel pump)
>> and
>> > it starts right up. As soon as I take the jumper off, the onan dies.
>> >
>> > The unit ran all weekend just fine. It died a couple of times on the way
>> > back from Austin and finally wouldn't start any more. Like whatever went
>> > wrong, happened over several hours before it totally failed. I
definitely
>> > want to hear what Duane's got to say about it. If anyone will know, he
>> will.
>> >
>> > Thanks again
>> > bdub
>> >
>> >

>> > >>My Onan will start and run as long as I have the Jim Bounds Priming
>> > >>Button pushed. When I let it go, the onan dies. Would this be typical
>> > >>of a bad oil pressure switch? It was a quart low on oil, but upon
>> adding
>> > >>the missing quart, it still won't continue to run.
>> > >>
>> > >>Any suggestions?
>> > >>
>> > >>Thanks
>> > >>bdub
>> > >
>> > >Billy -- when the primer switch is pressed it bypasses the low oil
>> > >pressure switch but also applies current to the fuel pump. It could
be a
>> > >low oil pressure switch but you can easily put a jumper across that
>> switch
>> > >and eliminate it to see if the Onan then runs. It could also be a
>> circuit
>> > >on the board or bad connections on the board. Try cleaning all the
>> > >connectors with some contact cleaner and see if it helps. If not,
you'll
>> > >probably need board repair. I had a similar problem several years ago
>> and
>> > >noticed some powdery residue by a couple of the electrolytic
>> > >capacitors. I replaced the capacitors with the closest value ones I
>> could
>> > >buy at Radio Shack and it cured the problem. One of the relays was not
>> > >closing properly and the capacitor was in that circuit.
>> > >
>> > >You might want Duane Simmons to give you his suggestions as he is very
>> > >familar with the operation of the control board and has given seminars
>> on it.
>> > >
>> > >Emery Stora
>> > >77 Kingsley
>> > >Santa Fe, NM
>> >
>> >
>>
>>
>>--
>>==========================================================================
======
>>Tim Dawson (tadawson) Owner/Engineer
>>TPC Services Bellnet: (972)-221-7385
>>Lewisville, Texas 75067 FAXnet: (972)-221-0393
>>"The world is complex. Sendmail.cf reflects this...."
>
>
Genef -- 77PB/ore/ca
GMC MOTORHOME INFORMATION
mr.erf
http://www.california.com/~eagle/

 

[bdub]

Thanks Tom

I've already made a note to add it to my list when I call tomorrow.

bdub

>Billy you may want to order the bracket from golbys as a ragusa order? It
>may be cheaper. the haeavy duty onan cast iron bracket is only $30 list and
>is RV-04. Call and add it if you want with your order.
>
>tom
>
>
>

> >Thanks Tim
> >
> >I think I might've fixed the problem today. I took the board off and found
> >that the upper right hand terminal of the K3 relay's solder joint had
> >broken. I also found where the solder trace to the top #5 terminal was
> >making intermittent contact because of corrosion. I repaired these two
> >places, resealed the board and remounted it.
> >
> >When I hit the start switch, I noticed that the choke now moves. I don't
> >think that was happening before.
> >
> >Anyway, I parked the coach yesterday with the reserve fuel tank switch
> >on. I wanted it to be nearly dry because I was thinking about dropping the
> >tanks and re-doing all the hoses and vents. Of course, the Onan wouldn't
> >start because it wasn't getting any fuel. Went and got a can of gas and
> >rigged up a temp fuel line for it. Then, before it started, the dern
> >starter fouled up on me. I took it off and the armature moves about a
> >1/16" in the wore out bushing. So I guess I've got to fix that before I
> >can see if the board works.
> >
> >I cleaned up the tools and shoved the Onan back into it's drawer but the
> >door wouldn't shut. I pulled it back out and looked behind it to see what
> >was making it not go in far enough but didn't see anything. I shoved it
> >really hard to try to make it go in enough. It didn't. Got to looking and
> >found the starter bracket was catching on the bottom of the
> >compartment. It's broken and hanging down too low. Now I bent the crap
> >out of it. Guess I've got another item to order from Golby's.
> >
> >I was thinking, while I tore the sheet metal and flywheel off the Onan,
> >about how appropriate GMC domino's really are. It seems that any time I
> >work on the GMC, there's something else that needs to be fixed too, and
> >then on and on, like a domino effect.
> >
> >Thanks for the suggestion. I saw that little relay shutting when I pushed
> >the starter button. Will keep it in mind when ever I get back to that
> point.
> >
> >Does anyone know a good source for Onan starter bushings besides Onan?
> >
> >Thanks
> >bdub
> >
> >
> >
> >

> >>If you remove the cover form the relay that powers the fuel pump, etc
> (the one
> >>with the single two pole contact) and push it in with your finger, do you
> >>hear the fuel pump run? If you crank the unit and do this, will it
> start and
> >>stay running? If so, I may have your solution - I just fixed a card
> for this
> >>problem for another netter. The voltage to that relay is dropped via a
> >>resistor, and it gets much less than 12 volts. If the cover has been
> pulled
> >>off the relay "carelesslt" (Can't come up with a better word . . .) the
> relay
> >>pole piece and spring can get pulled up away from the armature, so that the
> >>magnetic gap is much greater than it sould normally be, and there is not
> >>enough voltage to pull it in. (The other netter with this problem
> could start
> >>fine when plugged into shore power, but not from battery - the go/no go
> line
> >>on this is that sharp). To check this, look at the relay movable contact
> >>piece at the end opposite the contacts. If it is not sitting down as
> >>close to
> >>the relay coil/battery as it can, then gently adjust the spring at the
> rear of
> >>the relay until it does - the gap on this relay is typically 1/16" or so
> >>when set correctly.
> >>
> >>If the tests above do not reveal that you have this problem, then
> others may
> >>want to keep this in mind, since it appears to be a pretty easy
> situation to
> >>get into - I inadvertently did it to mine (and found/fixed it . .) and have
> >>dealt with the problem for one other person . .
> >>
> >>- Tim
> >>
> >> > Thanks Emery
> >> >
> >> > I can power the coil from the battery (which also powers the fuel pump)
> >> and
> >> > it starts right up. As soon as I take the jumper off, the onan dies.
> >> >
> >> > The unit ran all weekend just fine. It died a couple of times on
> the way
> >> > back from Austin and finally wouldn't start any more. Like whatever
> went
> >> > wrong, happened over several hours before it totally failed. I
> definitely
> >> > want to hear what Duane's got to say about it. If anyone will know, he
> >> will.
> >> >
> >> > Thanks again
> >> > bdub
> >> >
> >> >

> >> > >>My Onan will start and run as long as I have the Jim Bounds Priming
> >> > >>Button pushed. When I let it go, the onan dies. Would this be
> typical
> >> > >>of a bad oil pressure switch? It was a quart low on oil, but upon
> >> adding
> >> > >>the missing quart, it still won't continue to run.
> >> > >>
> >> > >>Any suggestions?
> >> > >>
> >> > >>Thanks
> >> > >>bdub
> >> > >
> >> > >Billy -- when the primer switch is pressed it bypasses the low oil
> >> > >pressure switch but also applies current to the fuel pump. It
> could be a
> >> > >low oil pressure switch but you can easily put a jumper across that
> >> switch
> >> > >and eliminate it to see if the Onan then runs. It could also be a
> >> circuit
> >> > >on the board or bad connections on the board. Try cleaning all the
> >> > >connectors with some contact cleaner and see if it helps. If not,
> you'll
> >> > >probably need board repair. I had a similar problem several years ago
> >> and
> >> > >noticed some powdery residue by a couple of the electrolytic
> >> > >capacitors. I replaced the capacitors with the closest value ones I
> >> could
> >> > >buy at Radio Shack and it cured the problem. One of the relays was not
> >> > >closing properly and the capacitor was in that circuit.
> >> > >
> >> > >You might want Duane Simmons to give you his suggestions as he is very
> >> > >familar with the operation of the control board and has given seminars
> >> on it.
> >> > >
> >> > >Emery Stora
> >> > >77 Kingsley
> >> > >Santa Fe, NM
> >> >
> >> >
> >>
> >>
> >>--
> >>==========================================================================
>======
> >>Tim Dawson (tadawson) Owner/Engineer
> >>TPC Services Bellnet: (972)-221-7385
> >>Lewisville, Texas 75067 FAXnet: (972)-221-0393
> >>"The world is complex. Sendmail.cf reflects this...."
> >
> >
> >

 

[bdub]

Thanks Gene

I'll check it out

bdub

>John Bush found that often the starter bracket is broken because the rubber
>motor mounts on the Onan are bad and let the starter rest on the pan..... so
>you might want to replace these mounts also.
>
>on my web page, Duane suggests it might cost almost as much to rebuild the
>starter as buy a new one and that the Onan number (he gives it) has changed.
>
>gene
>
>

> >Thanks Tim
> >
> >I think I might've fixed the problem today. I took the board off and found
> >that the upper right hand terminal of the K3 relay's solder joint had
> >broken. I also found where the solder trace to the top #5 terminal was
> >making intermittent contact because of corrosion. I repaired these two
> >places, resealed the board and remounted it.
> >
> >When I hit the start switch, I noticed that the choke now moves. I don't
> >think that was happening before.
> >
> >Anyway, I parked the coach yesterday with the reserve fuel tank switch
> >on. I wanted it to be nearly dry because I was thinking about dropping the
> >tanks and re-doing all the hoses and vents. Of course, the Onan wouldn't
> >start because it wasn't getting any fuel. Went and got a can of gas and
> >rigged up a temp fuel line for it. Then, before it started, the dern
> >starter fouled up on me. I took it off and the armature moves about a
> >1/16" in the wore out bushing. So I guess I've got to fix that before I
> >can see if the board works.
> >
> >I cleaned up the tools and shoved the Onan back into it's drawer but the
> >door wouldn't shut. I pulled it back out and looked behind it to see what
> >was making it not go in far enough but didn't see anything. I shoved it
> >really hard to try to make it go in enough. It didn't. Got to looking and
> >found the starter bracket was catching on the bottom of the
> >compartment. It's broken and hanging down too low. Now I bent the crap
> >out of it. Guess I've got another item to order from Golby's.
> >
> >I was thinking, while I tore the sheet metal and flywheel off the Onan,
> >about how appropriate GMC domino's really are. It seems that any time I
> >work on the GMC, there's something else that needs to be fixed too, and
> >then on and on, like a domino effect.
> >
> >Thanks for the suggestion. I saw that little relay shutting when I pushed
> >the starter button. Will keep it in mind when ever I get back to that
> point.
> >
> >Does anyone know a good source for Onan starter bushings besides Onan?
> >
> >Thanks
> >bdub
> >
> >
> >
> >

> >>If you remove the cover form the relay that powers the fuel pump, etc
>(the one
> >>with the single two pole contact) and push it in with your finger, do you
> >>hear the fuel pump run? If you crank the unit and do this, will it start
>and
> >>stay running? If so, I may have your solution - I just fixed a card for
>this
> >>problem for another netter. The voltage to that relay is dropped via a
> >>resistor, and it gets much less than 12 volts. If the cover has been
> pulled
> >>off the relay "carelesslt" (Can't come up with a better word . . .) the
>relay
> >>pole piece and spring can get pulled up away from the armature, so that the
> >>magnetic gap is much greater than it sould normally be, and there is not
> >>enough voltage to pull it in. (The other netter with this problem could
>start
> >>fine when plugged into shore power, but not from battery - the go/no go
> line
> >>on this is that sharp). To check this, look at the relay movable contact
> >>piece at the end opposite the contacts. If it is not sitting down as
> >>close to
> >>the relay coil/battery as it can, then gently adjust the spring at the
>rear of
> >>the relay until it does - the gap on this relay is typically 1/16" or so
> >>when set correctly.
> >>
> >>If the tests above do not reveal that you have this problem, then
> others may
> >>want to keep this in mind, since it appears to be a pretty easy
> situation to
> >>get into - I inadvertently did it to mine (and found/fixed it . .) and have
> >>dealt with the problem for one other person . .
> >>
> >>- Tim
> >>
> >> > Thanks Emery
> >> >
> >> > I can power the coil from the battery (which also powers the fuel pump)
> >> and
> >> > it starts right up. As soon as I take the jumper off, the onan dies.
> >> >
> >> > The unit ran all weekend just fine. It died a couple of times on
> the way
> >> > back from Austin and finally wouldn't start any more. Like whatever
> went
> >> > wrong, happened over several hours before it totally failed. I
>definitely
> >> > want to hear what Duane's got to say about it. If anyone will know, he
> >> will.
> >> >
> >> > Thanks again
> >> > bdub
> >> >
> >> >

> >> > >>My Onan will start and run as long as I have the Jim Bounds Priming
> >> > >>Button pushed. When I let it go, the onan dies. Would this be
> typical
> >> > >>of a bad oil pressure switch? It was a quart low on oil, but upon
> >> adding
> >> > >>the missing quart, it still won't continue to run.
> >> > >>
> >> > >>Any suggestions?
> >> > >>
> >> > >>Thanks
> >> > >>bdub
> >> > >
> >> > >Billy -- when the primer switch is pressed it bypasses the low oil
> >> > >pressure switch but also applies current to the fuel pump. It could
>be a
> >> > >low oil pressure switch but you can easily put a jumper across that
> >> switch
> >> > >and eliminate it to see if the Onan then runs. It could also be a
> >> circuit
> >> > >on the board or bad connections on the board. Try cleaning all the
> >> > >connectors with some contact cleaner and see if it helps. If not,
>you'll
> >> > >probably need board repair. I had a similar problem several years ago
> >> and
> >> > >noticed some powdery residue by a couple of the electrolytic
> >> > >capacitors. I replaced the capacitors with the closest value ones I
> >> could
> >> > >buy at Radio Shack and it cured the problem. One of the relays was not
> >> > >closing properly and the capacitor was in that circuit.
> >> > >
> >> > >You might want Duane Simmons to give you his suggestions as he is very
> >> > >familar with the operation of the control board and has given seminars
> >> on it.
> >> > >
> >> > >Emery Stora
> >> > >77 Kingsley
> >> > >Santa Fe, NM
> >> >
> >> >
> >>
> >>
> >>--
> >>==========================================================================
>======
> >>Tim Dawson (tadawson) Owner/Engineer
> >>TPC Services Bellnet: (972)-221-7385
> >>Lewisville, Texas 75067 FAXnet: (972)-221-0393
> >>"The world is complex. Sendmail.cf reflects this...."
> >
> >
>Genef -- 77PB/ore/ca
>GMC MOTORHOME INFORMATION
>mr.erf
>http://www.california.com/~eagle/

 

[emerystora]

>Thanks Tom
>
>I've already made a note to add it to my list when I call tomorrow.
>
>bdub
>
Bdub - since when did you move from Brownswood, TX to Bowie, Maryland?

Tom Warner's Ragusa list shows you at an address in Bowie, MD.

Emery Stora
77 Kingsley
Santa Fe, NM

 

[emerystora]

>If you remove the cover form the relay that powers the fuel pump, etc (the one
>with the single two pole contact) and push it in with your finger, do you
>hear the fuel pump run? If you crank the unit and do this, will it start and
>stay running? If so, I may have your solution - I just fixed a card for this
>problem for another netter. The voltage to that relay is dropped via a
>resistor, and it gets much less than 12 volts. If the cover has been pulled
>off the relay "carelesslt" (Can't come up with a better word . . .) the relay
>pole piece and spring can get pulled up away from the armature, so that the
>magnetic gap is much greater than it sould normally be, and there is not
>enough voltage to pull it in. (The other netter with this problem could start
>fine when plugged into shore power, but not from battery - the go/no go line
>on this is that sharp). To check this, look at the relay movable contact
>piece at the end opposite the contacts. If it is not sitting down as close to
>the relay coil/battery as it can, then gently adjust the spring at the rear of
>the relay until it does - the gap on this relay is typically 1/16" or so
>when set correctly.
>
>If the tests above do not reveal that you have this problem, then others may
>want to keep this in mind, since it appears to be a pretty easy situation to
>get into - I inadvertently did it to mine (and found/fixed it . .) and have
>dealt with the problem for one other person . .
>
>- Tim

This is the same relay that did not actuate properly when I had the
problem with my control board. The capacitor that I replaced to
correct the problem is in the power circuit to this relay. With a
bad capacitor the relay didn't get enough current to properly hold it
in. If this is your problem be sure to get the polarity right. The
electrolytic capacitor has a + and a - end. When Tim bent the spring
holder he may have adjusted it so that it needed less current to hold
it in and the original problem might have been in the power circuit
to the relay which may have been providing too low a voltage.

Emery Stora
77 Kingsley
Santa Fe, NM

 

[bdub]

hahaha, ...... yeah, I'll have to straighten that out with Jim at
Golby's tomorrow. That's just too far to go to pick up the parts.

bdub

>>Thanks Tom
>>
>>I've already made a note to add it to my list when I call tomorrow.
>>
>>bdub
>Bdub - since when did you move from Brownswood, TX to Bowie, Maryland?
>
>Tom Warner's Ragusa list shows you at an address in Bowie, MD.
>
>Emery Stora
>77 Kingsley
>Santa Fe, NM

 

[bdub]

Thanks Emery

If it gets down to things like that, that I don't even know what it is,
it's going straight to Orange, California. I don't trust me on things like
that. I reckon Duane can fix it with his eye's shut.

bdub

>This is the same relay that did not actuate properly when I had the
>problem with my control board. The capacitor that I replaced to correct
>the problem is in the power circuit to this relay. With a bad capacitor
>the relay didn't get enough current to properly hold it in. If this is
>your problem be sure to get the polarity right. The electrolytic
>capacitor has a + and a - end. When Tim bent the spring holder he may
>have adjusted it so that it needed less current to hold it in and the
>original problem might have been in the power circuit to the relay which
>may have been providing too low a voltage.
>
>Emery Stora
>77 Kingsley
>Santa Fe, NM

 

[bdub]

Thanks Rick

Will do. I know just the place in Brownwood.

bdub

>In a message dated 6/19/00 4:27:10 PM Mountain Daylight Time,

>
> > Does anyone know a good source for Onan starter bushings besides Onan?
>
>Bdub,
> Go to any auto electric shop that rebuilds Robert Bosch starters for
>European cars. (VW, Opel, some Italian cars, etc.) The Onan starter is a
>Bosch IIRC, and probably uses the same bushings as one of these others. Take
>old armature and bushings and housings along as samples. Shouldn't be over a
>buck or two each.
>
>HTH.
>
>Rick Staples
>'75 Eleganza
>Louisville, CO

 

[tim dawson]

Perhaps this may be a condition also, but it was definitely not the case on the
one that I repaired. I had my control card and genset (which works flawlessly)
as a reference to the one to fix, and the relay contact set was definitely
pulled way out from the normal position. Both boards had the same voltage
to the relay - one worked, the other didn't, with the only difference being
the contact setup. As Duane recently stated, if you are careless taking the
covers off these relays, they are easy to damage, and I suspect that this one
was pushed out of spec by someone innocently rocking the cover attempting to
get it to come off - any rocking in the long dimension drags the cover over the
contact spring, and you get this problem . . . .

- - Tim

> >If you remove the cover form the relay that powers the fuel pump, etc (the one
> >with the single two pole contact) and push it in with your finger, do you
> >hear the fuel pump run? If you crank the unit and do this, will it start and
> >stay running? If so, I may have your solution - I just fixed a card for this
> >problem for another netter. The voltage to that relay is dropped via a
> >resistor, and it gets much less than 12 volts. If the cover has been pulled
> >off the relay "carelesslt" (Can't come up with a better word . . .) the relay
> >pole piece and spring can get pulled up away from the armature, so that the
> >magnetic gap is much greater than it sould normally be, and there is not
> >enough voltage to pull it in. (The other netter with this problem could start
> >fine when plugged into shore power, but not from battery - the go/no go line
> >on this is that sharp). To check this, look at the relay movable contact
> >piece at the end opposite the contacts. If it is not sitting down as close to
> >the relay coil/battery as it can, then gently adjust the spring at the rear of
> >the relay until it does - the gap on this relay is typically 1/16" or so
> >when set correctly.
> >
> >If the tests above do not reveal that you have this problem, then others may
> >want to keep this in mind, since it appears to be a pretty easy situation to
> >get into - I inadvertently did it to mine (and found/fixed it . .) and have
> >dealt with the problem for one other person . .
> >
> >- Tim
>
> This is the same relay that did not actuate properly when I had the
> problem with my control board. The capacitor that I replaced to
> correct the problem is in the power circuit to this relay. With a
> bad capacitor the relay didn't get enough current to properly hold it
> in. If this is your problem be sure to get the polarity right. The
> electrolytic capacitor has a + and a - end. When Tim bent the spring
> holder he may have adjusted it so that it needed less current to hold
> it in and the original problem might have been in the power circuit
> to the relay which may have been providing too low a voltage.
>
> Emery Stora
> 77 Kingsley
> Santa Fe, NM
>

- --
================================================================================
Tim Dawson (tadawson) Owner/Engineer
TPC Services Bellnet: (972)-221-7385
Lewisville, Texas 75067 FAXnet: (972)-221-0393
"The world is complex. Sendmail.cf reflects this...."

 

[al chernoff]

>In reference to Paul Doane's post regarding Onan Paint. They are really
>proud of it aren't they.?
>I had removed my Onan, de-carboned it etc. I took a part off of it, took it
>to Home Depot and had them color match a quart of metal paint and sprayed
>my Onan. Looks great.
>
>Tom Bradley, Chandler, AZ

Hey Tom: when I was with you and we ran the onan, oil had dripped
out. what did you find caused that. Glad you got it fixed. Just
wait until you get your new ignition installed and you will see it
runs even better.
al