Community Forums

411jeff · 10-20-2014, 08:31 AM

It starts up fine, but after it does it's high & low idle test, it shuts down with error 25. I read the tech manual about checking the governor. What's strange is if I put a load on it right when it starts sending power, it doesn't shutdown. I just wanted to see if anyone knows why it's ok if I put a load on right away. I can even remove the load and it will continue to run, but if I don't put a load immediately, it will shut down with error 25. Almost forgot. It will also surge back and forth sometimes during the initial start up. Thanks.

94-Newmar · 10-21-2014, 02:54 AM

Jeff, 25 is a fairly rare error to have. Unfortunately, since it's an inverter type generator, you must use a tachometer to test and set the idle and high speeds as the Hertz/Frequency is not determined by the engine speed as with non-inverter generators. It's attempting to regulate engine speed but the engine is not responding to the commands within the timeframe. This could be a governor controller error, a sticky governor or even a fuel delivery problem.

With that being said and you mentioning it surging during startup, the absolute first step I would take is to replace the fuel filter. After replacing the fuel filter I would perform a fuel system test. It is described in the service manual quite well. If you don't have it, here it is:

Quote:

Fuel Flow Test
1. Disconnect the fuel return hose from the line to the supply tank and point the end into a quart (1 liter) or larger container that has volume
graduations.

2. Prime the genset by pushing the Start/Stop switch to STOP and holding it there for the duration of the test. Flow should not be less than 200 ml (0.4 pints) per minute.

3. If flow is less than specified, replace the fuel filter. If that does not help, look for other restrictions in the fuel system. Last, replace the fuel
pump. The pump is not serviceable

Some minor surging is normal during startup, but generally smooths out within a few seconds. Keep us posted....

EDIT: Jeff, we recently discussed an Error 19 on your unit in this thread here: http://www.irv2.com/forums/f258/onan...-a-220848.html

During this discussion you indicated the error had gone away after disconnecting/reconnecting the harness leading to the governor. I suggest this new Error 25 indicates you have some issues going on with the governor itself OR you have continuing problems in that wiring harness that controls the governor.

411jeff · 10-21-2014, 10:00 AM

I started it up yesterday and everything was fine. No surge and no error 25. I'll start it up again today. I did just replace the fuel filter a month ago after the error 19, but I'll run the fuel test this weekend. And thanks for all your help. I'll let you know what happens.

411jeff · 10-27-2014, 09:47 AM

I tested the fuel flow and it was over 200 mi. I looked to test the governor, but I'm not sure I'm doing it correctly. I have attached 3 pictures. 1 is the governor. 2 is where I pushed it 1/2 inch to clockwise and 3 is how far I was able to push it. If I'm supposed to turn it at the top near the spring by hand, I can't. It's too tight to turn by hand near the spring at the top. Please let me know what you think. Thanks

411jeff · 10-27-2014, 09:48 AM

I'm not sure what happened by picture 2 & 3 are upside down.

411jeff · 10-31-2014, 03:25 PM

Just started it up again and it shutoff with the fault 25. I restarted and put a load on it once I saw it generating electricity. And it didn't shutdown. So if I put a load on it right off the bat, it will run. And it will continue to run after the initial load is removed.

94-Newmar · 10-31-2014, 07:34 PM

Jeff, during intial startup the unit should go into high idle, then after 60 seconds or so it will go back to a low idle if no loads are attached. Is the error and subsequent shudown occurring after it goes back to idle or before? (with no load on it)

N6CUS · 10-31-2014, 07:57 PM

My Onan HDKAK 8500 starts at random by itself and runs and I come home and its running
or I get up at home and its running again,

What is going on with that?

411jeff · 11-01-2014, 12:19 PM

Every time it has shut down has been with no load, after initial start up and it goes to the low idle mode (except yesterday). Yesterday was the first time it killed before going to the low idle. I then restarted it and put a load on it as soon as I could. It kept running. Even ran after I removed the load and it went into the low idle, it kept running. That seems strange to me. If I put a load on it ASAP, it will run. Seem like the problem would cause it to shutdown no matter. Thanks for your continued help. Jeff

94-Newmar · 11-01-2014, 03:56 PM

If it's running under load say for an hour or so and you remove the load or just shut the breakers off on the genset and it goes back down to idle, will it idle indefinitely or will it toss a 25?

I am trying to determine if its only an issue when the unit is not at operating temp (cold).

411jeff · 11-01-2014, 05:32 PM

Even if I only run it under load for 2 or 3 minutes after start up, it will continue to run at idle speed with no load after that. But I can try some more tests with it tomorrow if you want be to do some exact timings. What I did yesterday was to turn the microwave on for 2.5 minutes as soon as I saw power going to the RV....maybe 20 or 30 seconds after I started the Onan. After the microwave shut off, the Onan idled down. I stayed with it at least another 8 to 10 minutes at idle speed and it didn't shutdown. Then I powered off the Onan.

411jeff · 11-02-2014, 03:05 PM

Just did some more runs.....
1st start - ran at high idle (no surging) until 1:12 and then killed.

2nd start - ran at high idle and surging until :45 seconds. lower idle at 1:08. killed at 2:10

3rd start - ran at high idle with surging. lower idle at 1:06 & surging stopped when dropped to lower idle. At 1:58 it dropped to an even lower idle. killed at 2:15

4th start - ran at high idle with surging. lower idle at 1:00 & surging stopped at 1:15. At 1:50 it dropped to an even lower idle. killed at 5:20

5th start - ran at high idle with surging. lower idle at 1:00 & surge ended at 1:04. At 1:59 it dropped to an even lower idle. It ran for over 24 minutes then I shut it off.

There was never any load put on during any of this. And always error 25.
I live in Louisiana so it's not that cold here and it did this a few weeks ago when the temps were in the high 80's.

I hope this might give you some good clues. Thanks again. Jeff

94-Newmar · 11-08-2014, 04:12 AM

It certainly follows a pattern based upon it's running temperature.

When the unit is at ambient temp it always fails.
When the unit is at operating temperature it never fails.

Can you make a short video of the unit surging during it's initial startup when it's not at operating temperature? I need to know what you are referring to as "surging" as compared to what I know as surging.

This is all starting to sound like a thermal related event to me. I hesitate to throw parts at something when I am not 100% sure of the actual problem. I will make a phone call today to a good friend with Onan who is my go-to person when odd problems like yours occur.

411jeff · 11-09-2014, 10:47 AM

I think a lower temp makes the problem worse, but it has happened in warm temps too. Yesterday morning it was colder and it killed more often and sooner.
Below is a link to a video on Youtube of the "surge". This was my second start this morning. It killed on the 1st start. Yesterday once I got it running , I kept it running for over 12 hours. We were tailgating at a football game.

https://www.youtube.com/watch?v=pbAr4bDf31k

Thanks - Jeff