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RVing message boards => Tech Talk => Topic started by: CybexRV on September 23, 2017, 09:50:26 AM

Title: Need Help with Onan Generator
Post by: CybexRV on September 23, 2017, 09:50:26 AM
I just bought a used fifth wheel toy hauler with an Onan 4K KY Spec L generator installed by the manufacturer from a private owner.  I didn't look close enough (nor did he point it out) but it appears the previous owner ran the generator with the hatch door closed and the heat buildup warped the generators enclosure enough that the service door will not properly fit and lock down.  He also removed one of the service panel latch assemblies I am assuming to hide the issue.  It is not terribly warped to the point I can not run the generator, but it would be nice to have it as it should be.

I am looking for a reasonable price on a replacement generator enclosure and service panel latch assembly if anyone has one or can refer me in any direction.  I tried finding online, but no luck.

Or, if anyone has ideas of how to fix what I have that would be great too!

I have included a picture of the tag on the generator hoping that it is useful.
Title: Re: Need Help with Onan Generator
Post by: Roy M on September 23, 2017, 10:22:10 AM
Is the trailer manufacturer still in business? Maybe they could source one from their supplier. Other than that, an rv salvage yard might be the best bet.
Title: Re: Need Help with Onan Generator
Post by: kdbgoat on September 23, 2017, 01:35:42 PM
Why would the hatch have to be open? They're designed to run while going down the road.
Title: Re: Need Help with Onan Generator
Post by: Vw triker on September 23, 2017, 03:10:47 PM
The housing is fiberglass I think. Remove the generator , should have 4 bolts holding the top half on, they might have come loose making it appear to be warped
Title: Re: Need Help with Onan Generator
Post by: Gary RV_Wizard on September 24, 2017, 09:30:32 AM
Why would the hatch have to be open? They're designed to run while going down the road.

Just piss-poor engineering. Much of what goes into an RV isn't worthy of the terms "designed" or "engineered".  "Thrown together" would perhaps be more apt.  I'm serious - most of the "design" is done by es-assembly line techs who guestimate how to fit things in and hook them up. Nobody is analyzing air flow or cooling requirements, or testing to validate that it is adequate in hot weather or while the rig is moving down the highway at 60+.
Title: Re: Need Help with Onan Generator
Post by: wackymac on September 24, 2017, 07:16:03 PM
Is it possible that the generator doesn't have enough clearance around it for cooling?  The Onan installation manual specifies how much clearance to leave for proper cooling.
Title: Re: Need Help with Onan Generator
Post by: Harley145 on September 25, 2017, 12:04:37 PM
I had one damaged in shipping and you can probably obtain one from ONAN, but they are not cheap ! >:(
Title: Re: Need Help with Onan Generator
Post by: CybexRV on September 26, 2017, 08:28:33 AM
Thanks for all the replies, I have to agree with Gary.  There is literally no venting or fan system for airflow except from the openings in the bottom plate in the unit or the fifth wheel enclosure, so I would not even feel comfortable running the generator while going down the road.  Especially after seeing the damage to the backside of the hatch door.  This generator only has 96 hours on it, can't image what the additional damage would be if I continued for another few hundred hours.  There is some foil backed insulation, but only on the back back wall.    Was thinking of cutting the melted part out of the hatch door and replacing with some venting.

The generator enclosure is fiberglass and I did check to see if it was unbolted or loose just as a part of going over everything, but it is warped no doubt.  And even if the RV enclosure area is not up to spec, there is nothing I can do about it at this point.  There is no room to expand in any direction.

We are headed out for the maiden voyage tomorrow, so for now I will just run it with the RV hatch open when we use it.  But I plan to add some venting and maybe even a fan to create ventilation that comes on at startup.  I thought Forest River was one of the better made, but I guess none of them are perfect.
Title: Re: Need Help with Onan Generator
Post by: Gary RV_Wizard on September 26, 2017, 11:36:02 AM
RVs are designed and built with what amounts to shade tree engineering. Nobody does an engineering analysis on each element - they just go with experience from previous models (which may or may not have been all that great) and extrapolate to the new situation. If enough complaints come in, they may learn something for the next go-around, but chances are any individual problem will only effect some owners, some of the time, and word won't get back to the factory guys.

RV layouts change all the time, trying to find floor plans, features and price points that attract more buyers.  A modified design moves something or increases size (e.g. bigger tv, more kilowatts) or adds something (e.g. an electric fireplace) and the so-called engineering group races to make changes to include them while not requiring new wiring harnesses, build procedures, or expensive components.  Somebody eyeballs the changes and says "looks OK" and that's pretty much the extent of it.

Several years ago I had the opportunity to chat at length with Fleetwood's Production Manager, responsible for all their motorhome product assembly lines. His biggest headache at the time was rapidly changing expectations for TVs in the motorhomes. Flat panel tvs were quickly increasing in size and quality and having the latest & best tv was a major selling point in mid-high end coaches. Every time the marketing types came in with an improved tv offering, engineering did a quick revamp and they shoved it onto the assembly line.  And the problems snowballed. Overheated electronics, overloaded circuits, inadequate mounts for the larger/heavier tvs, etc. He started to veto production changes because they couldn't provide assurance the changes would be of decent quality, but they had no process in place to do that and no time to do it if they did. So it was "test it in the field" all the way. The engineering guys gradually learned what had to be done to handle the new and larger tvs and the problems dies down, but meanwhile hundreds of coaches had been built and sold and the inadequate designs delivered to buyers. The problems went on for a couple years but once they were post-warranty the factory loses sight on them except through owner clubs and factory-sponsored rallys.