Onan Fuel Supply

[Melbo]

Got the onan started and it runs well. I makes electricity (126 volts with no load) but does not shut down with the switch so some more trouble
shooting to solve that. I may have to order a board from JimK. I have been drawing fuel from a separate gas container. Now to get gas from a normal
fuel supply. My question is how important is it to remove and check the integrity of the fuel tanks. My motorhome was sold to Louisville KY and then
to Albuquerque NM. I grew up in Illinois and I know gas tanks rust out in vehicles there and this is a 45 year old motorhome. Is it necessary or
just good preventative maintenance to pull the tanks. I will be replacing all the fuel lines. I have not checked what kind of pollution control
venting hoses there are but I'm sure they will need attention too. If they absolutely need to be removed cleaned and coated or at least cleaned now is
the time and I am looking for guidance.

Thanks

Melbo
--
Albuquerque NM Bus Conversion 1978 MCI 1973 GMC

 

[RF_Burns]

Which switch is not working in the shut-down position? The remote switch by the door or the switch right on the control board on the generator. The
switches are wired in parallel and simply switch to ground for either function.

Shut-down position simply shorts a rely coil to ground causing it to drop out. The remote switch by the door can be disassembled (carefully) and
cleaned. It could also be the remote switch connector which is usually under the coach near the generator. Cut the connector out (its not
weatherproof) and make new direct connections and waterproof them.

If its the switch on the board that is not working, then its likely a faulty switch (again not weatherproof). Mine is a small switch available from
places like Digikey.com.

--
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that

 

[Carl Stouffer]

Unless you have holes in the floor (in the right places), you'll need to drop the tanks in order to replace the fuel lines anyway.

My coach was in semi constant use when I bought it so the fuel tanks were nice and clean. Also it was a Texas/Arizona coach. You might find the
tanks to be in better shape than you expect, or they might have a bunch of crud in them if the coach had been sitting for a few years.
--
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles,
Solar battery charging. GMCSJ and GMCMI member

 

[jim kanomata1]

Melbo,
I would be careful on how to lay out the generator 1/4" hose as hose can
kink when the unit is pushed in.

> Which switch is not working in the shut-down position? The remote switch
> by the door or the switch right on the control board on the generator. The
> switches are wired in parallel and simply switch to ground for either
> function.
>
> Shut-down position simply shorts a rely coil to ground causing it to drop
> out. The remote switch by the door can be disassembled (carefully) and
> cleaned. It could also be the remote switch connector which is usually
> under the coach near the generator. Cut the connector out (its not
> weatherproof) and make new direct connections and waterproof them.
>
> If its the switch on the board that is not working, then its likely a
> faulty switch (again not weatherproof). Mine is a small switch available
> from
> places like Digikey.com.
>
> --
> Bruce Hislop
> ON Canada
> 77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.1 ton front end
> http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
> My Staff says I never listen to them, or something like that
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

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

 

[Melbo]

RF
It is the switch on the generator board that does not shut the unit down. I have researched the circuits and trouble shooting guides on line and have
a plan to see where the malfunction is. I just want to be sure the low oil (#12) is functional so as to prevent catastrophic failure.

Carl
If the tanks need to be removed to replace the fuel lines I guess it is settled. The tanks come out. The coach has been setting for the last 12
years. Hard to know how much setting it did before that but good fuel for the onan is important and will need to be available for the 455 which is
the next step in the process of waking this motorhome up.

Thanks for the help

Melbo
--
Albuquerque NM Bus Conversion 1978 MCI 1973 GMC

 

[john r. lebetski]

The tanks can be spotless in side (or not, usually not in between). The problem is the old rubber fiel lines that are not barricade ethanol resistant.
They break down and can leak fuel out or air in. Switch to all baricade tops of tanks, at selector and frame to engine and tank to Onan. I use in
line metal filters just before engine fuel pump and just before Onan . And tygon from drawer to Onan pump as it behaves better in that tight space.

--
John Lebetski
Woodstock, IL
77 Eleganza II

 

[johnny]

The switch is a common failure item on the circuit board. If the remote switch works, then the local switch itself is suspect. All the oil pressure
switch does is pull a wire to ground. I don't have the circuit in front of me, but it tells which connector on the circuit board connects to the oil
pressure switch. With the set running, ground that connector with a clip cord. In a few seconds (there's a time delay built into the circuit) the
engine should shut down. If you suspect the pressure switch itself, simply replace it. It should be a 5 PSI oil pressure sense switch which you can
find at the parts house.

--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" - ol Andy, paraphrased