Community Forums

HamboneTHW · 09-28-2018, 04:21 PM

Quote:

Originally Posted by Old Scout

….as Jim and Wil pointed out, there is a known conflict between the Onan and the Xantrex inverter. Seems Onan doesn't like the multiple 12v outputs from both the Cummins alternator and the inverter. Need to shut down the charge function on the Xantrex inverter just after the Onan comes on line with power. Think Cummins can be running or not. If you shut off the Onan for any reason, you have to repeat the process and turn off the Xantrex charge function....

Dean,

Out of curiosity, it has never done this in previous trips and I have never shut it off before.

But, it's certainly worth a try...

Thanks!

Old Scout · 09-28-2018, 04:24 PM

….whole right side of wall panels under dash, in front of passenger seat, are velcro-ed in place....two separate panels to remove....start with right panel.....no trick

csbaer · 09-28-2018, 04:26 PM

Our intermittent shut down problem indicated a bad coolant temp sensor. I ordered the part, took off the cover to swap it out, and found the wire connected to the coolant temp sensor was just sloppy loose. I snugged it up and it's run flawlessly ever since. Kept the sensor for a spare.

DrDaveMA · 09-28-2018, 10:57 PM

Ham, the Onan generator will flash a code when it shuts down in some way other than normal. When yours does shut down read the code on the switch in the console or on the genny itself, that will get you in the right area. If there are no codes shown (it is 2 digits, usually first number is 3) and repeats, follow the chaffed wire suggestion or the switch in the console. There is also a stop signal that will come from the inverter that will cause the genny to stop.

To read the codes look at the switch, you might see 3 flashes followed by 8, that tells you your error is a 38. Look it up in the manual and you are headed in the right direction.

c_oneil · 09-29-2018, 08:21 AM

Quote:

Originally Posted by HamboneTHW

Carter,

Where exactly do I find the sender?

It quickly goes back and forth from E to F, then at some point during the drive it will slowly climb back to F and stay there.

I'll certainly check for chafed wires.

Thanks!

The fuel sending unit is on the side of the fuel tank at the top on the drivers side. There is an access hole through the frame rail in the front wheel well area. Turn the front wheels towards the right all the way to the stop and you can squeeze in behind the tire to get to it.

HamboneTHW · 10-21-2018, 05:29 PM

For anyone following this...

I topped off the oil in the generator (was just about halfway between Add 1 qt and Full marking) before adding oil.

I also turned off the "charger" function on the Xantrex after starting the motor.

Both the trip to and from (only a 45 minute drive in each direction) I had no issues running the generator while driving.

I'll hope to add this one to the "resolved gremlins" pile

Mark D · 10-21-2018, 05:54 PM

Quote:

Originally Posted by HamboneTHW

So we have had our 2005 Limited 40 FDTS since April and used it 5 times. I've never had an issue with the generator until our trip this weekend. I went to pull out of the driveway with the generator running. Everything seemed fine, but 5 minutes down the road the generator shut off. I started it back up, it ran for a few minutes then shut off. This went on about 3 or 4 times. Finally I gave up. It was 68 degrees out and the fans kept me cool. When we arrived about 40 minutes later, I extended the slides and jacks and shut the main engine down. I restarted the generator and it ran flawless the rest of the weekend. I went to drive off and the generator started shutting down again. I was unable to stop and open the generator bay to look at the code to determine the reason for shutdown.

This trip I also noticed my fuel gauge would go from E to F (tank is full) at random times.

1. Has anyone had this problem with their fuel gauge?
2. If so, what is the fix?
3. Does the gauge issue affect the generator shutting down (i.e. does the electronic signal from the fuel gauge transmit to the generator?)?
4. Any further ideas for troubleshooting?

As always, thank you in advance for your help and insight.

The fuel gage wouldn't impact the generator running. It would drop off if the fuel drops too low. If that happens you will know, it will be harder to restart and would stumble some.

Our last motorhome had an issue similar. We brought it in to Cummins and they tested it for hours and it ran fine. They replaced the oil sensor and sent me on the way. It was better but would cut out when driving.

Our new coach has a larger and newer unit and has no issues running while driving.

What I learned while trying to figure out the issue was first only use Onan oil filters. They have an oil bypass port that helps with the oil pressure, not sure exactly what its called but some aftermarket filters do not have it. Second too much oil can cause the same issue.

If you watch the blinking lights on the generator it will tell you if it is low oil pressure. You need to download the specific manual and it will tell you how to check the shut down code.

Old Scout · 10-21-2018, 06:03 PM

...interesting theory on oil pressure and an Onan brand filter w/by-pass valve....In the absence of a blinking code, I would again suggest starting Onan first, then shut down charger function on inverter, then start the Cummins....Onan seem to always like multiple 12v sources, eg, the Cummins alternator and the inverter/charger....see what happens.....