This is for a friend who has problems with gen set.
The gen runs fast and does not put out any power and no power shows on gauge and no polarity light. I came up with some ideas but decided to ask this so the many brains here on forum can help . Mel the owner is a forum member but has not posted ever so not savvy with the process.
All ideas are wanted.
Thanks from me in Mexico
Johnh
Just stabbing in the dark since no info on generator make/model, but on my previous coach, I had to start the Generac generator with the breakers on the generator panel OFF. Once it spooled up for a minute or so, flipping on the breakers activated the excitation circuit, and got the juice flowing. Otherwise it was a brick. Give that a try? Woody.
Our 95 has a reset button on the front of the control box. Pops out when it needs reset ( I guess).
The only time I've messed with it was unnecessary and didn't help the situation.
Our '93 U280 has the 10Kw PowerTech with the very simple switch setup on the control box. Just has a start/stop/preheat switch, two big 45A circuit breakers, and a pop-out "Push To Reset" button (which I have never had to reset). In the 8 years we have owned our coach, the generator has literally operated 100% perfectly, so I've never had to do any trouble shooting.
If the engine runs, but the generator doesn't put out any juice, I would guess the problem may be inside the control box. Loose/dirty connection, chafed/shorted wire...some random fault caused by vibration?
But like I said, just a guess. Thread linked below may shed some light?
Powertech 10 problem (https://www.foreforums.com/index.php?topic=14894)
Reseat the plug-in relays inside the generator control box.
And......
Chuck, how do you keep the gen-set so clean?
Never use it? 🤣
Oh, it gets plenty dirty...dusty, mostly. That's from an old photo session when I was doing my first generator oil and filter change after buying the coach. I like to clean up a machine before I work on it - and after.
It has probably never looked that good since then.
I am 2500 miles from it but think it is a 8kw side mounted in the gv.
I will talk to him on phone and suggest the points mentioned as these where also my first thoughts
Johnh
Just talked to him and it is a 6kw propane powered Onan side mount. He will check Breakers etc.
Johnh
Yup, on generator breakers (two) OFF and back ON.
After that he can check for 120 VAC at the junction box where generator wiring connects to coach wiring OR at the ATS.
And, I "assume" by "runs fast" that it runs at normal speed. If not, totally different issue.
Our 1993 U300 has a 10K side-mounted generator. Looks a lot like the picture, only not so clean. I'd check the reset button first. Remember that the "brain" needs a couple of minutes of running before it allows the electricity out of the generator and into the coach.
If that doesn't work, make sure everything is unplugged and open the box shown in the pictures. Make sure that all connections are good. Then close it up and check the transfer box.
Please, now that we know what generator he has, let's only post responses applicable to his propane generator.
BTW, assume this is the 6.5kw propane generator in the forward, driver's side bay so it is likely this is a U225 or U240 if coach is between 1991 and 1995.
More info. It is an Onan 6500 and I have had him check and clean out fuses, switches etc. It has not run in over 12 months due to not using coach so I told him off for not doing that. Linkages are stiff so working on that and Mel sent me an audio video of it running and it sounds like it is overspeeding to me and he said when he turns it off as it shows down he gets 120 for about 20 secs before stopping. Any thoughts please.
Johnh
I have that same generator, run by propane, and have not experienced this problem but it sounds like the governor needs attention for sure.
The fact that he does get power when it slows down is a good sign!
You are on the right track to make sure the throttle linkage is free.
I believe (been awhile since I worked on one) that there is choke. Make sure it pulls off.
The good news is that unlike gasoline generators, non-use will not cause a carburetor to gum up.
Worked on one in southern Mexico many years ago with same symptoms (over-speeding). After removing a mouse nest from the top of the engine (encompassing the throttle linkage) it works fine.
And, until he gets RPM in-range, have him turn off the on-generator breakers. No point in taking a chance with high voltage to coach appliances.
Air restriction?? Acting as if the choke is stuck? Just a thought........ ours is diesel. 8)
Now that we know what model generator, and not only do I have the dame model but I spent four years relying on a 4KW Onan Emerald II for winter power, "I know stuff."
A drop of oil on the governor shaft where it goes through the engine housing. That's on top just behind the flywheel. Do the same thing to the throttle shaft. Then gently work the linkage back and forth until you can reach the idle stop. Start the generator, and if necessary help the shift linkage down towards the idle stop. Allow the engine to warm up so that warm oil can soak the governor output shaft from the inside.
IF you own a multi-meter that measures frequency* in Hertz or the more modern cycles per second, no load RPM equals 62 Hz, full load RPM equals 58 Hz.
Harbor Freight $8. Fluke, if you have to ask, go to Harbor Freight.