Strange Onan problem

[johnny]

GeorgeZ and I are trying to find a recurring problem with his genset. To set the stage, it has a prime circuit which has worked correctly for a
looong tome. The priming circuit Takes 12 volts from the 12v feed to the gauge panel through a fuse and momentary switch to the Onan remote feed 12v
when running wire.
Symptom is, the set will run until it warms up and then will blow the fuse on the engine control card (Dinosaur board) >and the fuse feeding 12V to
the primer button. We tested it with an ammeter across the fuse on the card. When it fails the current jumps to the maximum my meter is capable of
(30 Amps) indicating a dead short someplace. When inspected the primer fuse is also blown.
I can think of nothing but a short on the remote/gauge panel but open to speculation.
We're going back at it Monday with my Molex tools and do some selective disconnecting to try to find it... but open to ides.

Thoughts?

--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

 

[powwerjon]

Have you checked the wiring that goes from the back of the generator to the
inside panel. There is a plug and a lot of times the plug is corroded and
typically just replace with butt splices or solder and heat shrink. Look
in manual 24C-47 & 48.

J.R. Wright
GMC Great Laker
GMCGL Tech Editor
GMC Eastern States
GMCMHI
TZE Zone Restorations
78 Buskirk Custom 29.5' Stretch
75 Avion (Under going Frame up Restoration)

On Sat, Feb 26, 2022 at 9:01 AM Johnny Bridges via Gmclist <

> GeorgeZ and I are trying to find a recurring problem with his genset. To
> set the stage, it has a prime circuit which has worked correctly for a
> looong tome. The priming circuit Takes 12 volts from the 12v feed to the
> gauge panel through a fuse and momentary switch to the Onan remote feed 12v
> when running wire.
> Symptom is, the set will run until it warms up and then will blow the fuse
> on the engine control card (Dinosaur board) >and the fuse feeding 12V to
> the primer button. We tested it with an ammeter across the fuse on the
> card. When it fails the current jumps to the maximum my meter is capable of
> (30 Amps) indicating a dead short someplace. When inspected the primer
> fuse is also blown.
> I can think of nothing but a short on the remote/gauge panel but open to
> speculation.
> We're going back at it Monday with my Molex tools and do some selective
> disconnecting to try to find it... but open to ides.
>
> Thoughts?
>
> --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
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>

 

[George Z]

JR
Thanks for your reply. I replaced that plug and socket a number of years ago.

Good news is the Onan seems to be running good now. I disconnected the fuel cut-off solenoid. I then connected a fused jumper from starter batt stud to solenoid power wire. Onan ran for 7 minutes until I shut it down. Reconnected solenoid power feed wire. It seemed to connect with a solid feel. I think the unprotected edge of the connector may have been shorting out. I ran the Onan for short periods as I buttoned it back together. I plan to run the Onan today for a couple of hours while I replace my dash radio.

Thanks again!

George Zhookoff

>
> Have you checked the wiring that goes from the back of the generator to the
> inside panel. There is a plug and a lot of times the plug is corroded and
> typically just replace with butt splices or solder and heat shrink. Look
> in manual 24C-47 & 48.
>
> J.R. Wright
> GMC Great Laker
> GMCGL Tech Editor
> GMC Eastern States
> GMCMHI
> TZE Zone Restorations
> 78 Buskirk Custom 29.5' Stretch
> 75 Avion (Under going Frame up Restoration)
>
>
>
>> On Sat, Feb 26, 2022 at 9:01 AM Johnny Bridges via Gmclist <

>>
>> GeorgeZ and I are trying to find a recurring problem with his genset. To
>> set the stage, it has a prime circuit which has worked correctly for a
>> looong tome. The priming circuit Takes 12 volts from the 12v feed to the
>> gauge panel through a fuse and momentary switch to the Onan remote feed 12v
>> when running wire.
>> Symptom is, the set will run until it warms up and then will blow the fuse
>> on the engine control card (Dinosaur board) >and the fuse feeding 12V to
>> the primer button. We tested it with an ammeter across the fuse on the
>> card. When it fails the current jumps to the maximum my meter is capable of
>> (30 Amps) indicating a dead short someplace. When inspected the primer
>> fuse is also blown.
>> I can think of nothing but a short on the remote/gauge panel but open to
>> speculation.
>> We're going back at it Monday with my Molex tools and do some selective
>> disconnecting to try to find it... but open to ides.
>>
>> Thoughts?
>>
>> --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
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:

 

[jim kanomata1]

Be sure to run with a load as that is the best way to know it is ok.

> JR
> Thanks for your reply. I replaced that plug and socket a number of years
> ago.
>
> Good news is the Onan seems to be running good now. I disconnected the
> fuel cut-off solenoid. I then connected a fused jumper from starter batt
> stud to solenoid power wire. Onan ran for 7 minutes until I shut it down.
> Reconnected solenoid power feed wire. It seemed to connect with a solid
> feel. I think the unprotected edge of the connector may have been shorting
> out. I ran the Onan for short periods as I buttoned it back together. I
> plan to run the Onan today for a couple of hours while I replace my dash
> radio.
>
> Thanks again!
>
> George Zhookoff
>
>

> >
> > Have you checked the wiring that goes from the back of the generator to
> the
> > inside panel. There is a plug and a lot of times the plug is corroded and
> > typically just replace with butt splices or solder and heat shrink. Look
> > in manual 24C-47 & 48.
> >
> > J.R. Wright
> > GMC Great Laker
> > GMCGL Tech Editor
> > GMC Eastern States
> > GMCMHI
> > TZE Zone Restorations
> > 78 Buskirk Custom 29.5' Stretch
> > 75 Avion (Under going Frame up Restoration)
> >
> >
> >
> >> On Sat, Feb 26, 2022 at 9:01 AM Johnny Bridges via Gmclist <

> >>
> >> GeorgeZ and I are trying to find a recurring problem with his genset.
> To
> >> set the stage, it has a prime circuit which has worked correctly for a
> >> looong tome. The priming circuit Takes 12 volts from the 12v feed to
> the
> >> gauge panel through a fuse and momentary switch to the Onan remote feed
> 12v
> >> when running wire.
> >> Symptom is, the set will run until it warms up and then will blow the
> fuse
> >> on the engine control card (Dinosaur board) >and the fuse feeding 12V to
> >> the primer button. We tested it with an ammeter across the fuse on the
> >> card. When it fails the current jumps to the maximum my meter is
> capable of
> >> (30 Amps) indicating a dead short someplace. When inspected the primer
> >> fuse is also blown.
> >> I can think of nothing but a short on the remote/gauge panel but open to
> >> speculation.
> >> We're going back at it Monday with my Molex tools and do some selective
> >> disconnecting to try to find it... but open to ides.
> >>
> >> Thoughts?
> >>
> >> --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
> >> _______________________________________________
> >> GMCnet mailing list
> >> Unsubscribe or Change List Options:
> >>
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>

--
Jim Kanomata ASE
Applied/GMC, Newark,CA
jimk
http://www.gmcrvparts.com
1-800-752-7502