Gen runs when parked, not when moving

[jeffprupis]

8K Onan runs fine when we're parked. When I try to run it when the engine (coach) is running she starts up fine, transfer switch switches to generator, then it dies after 60-90 seconds. If I park, kill the coach engine generator runs fine. Any ideas would be appreciated as always. TIA Have service appointment scheduled for next week, but would love to solve this on my own (with your all's help, of course).

[David T. Richelderfer]

Is the AGS (auto gen start) shutting down the generator because the batteries are charged up?

[jeffprupis]

AGS is set to off.

[Keith Moffett Co-Admin]

Have you looked into a fuel line or feed problem?  It may be a stretch but if a line is partly blocked then demand increases with both running. 

[Larry Dedrick]

I'm with Keith regarding potential fuel problem. What is your fuel level? 1/4 tank of fuel will soon stop feeding fuel.

              Larry D

[David T. Richelderfer]

Is there an error flash code on the gen start buttons?

[Bryan Schmidt]

Jeff:

We have the same yr and model coach.  I'd like to propose an alternate issue/solution, something very similar that we experienced 9+ yrs ago back in 07'.

Is your issue something that just started recently, (E.G: the Onan used to start & run always after the coach was running) or some new issue you just happened to run across now?  That might help direct the diag effort.

Anyway, back in 07, Our similar sounding problem was that our Onan would not continue to run after its initial startup and its 60+ sec Power Delay settling time if started after the coach diesel was running.  But if I started the Onan first, let it settle and complete its switch over to Gen-Power (as shown on the Alladin), then started the coach diesel, that sequence of steps might work, maybe 1 out of 4+ times and the Onan would continue to run.   

To try to help drag the problem further: (with the coach parked & level, diesel fuel tank 1/2+ full to eliminate possible fuel issues)
- open the generator slide so that you can see the small Onan display next to the START switch
- start coach diesel and let it idle
- start Onan, wait for its initial 60+ sec Power Delay settling time, then the Onan should die
- read out the Onan fault code on the blinking display

The Onan fault code was some obscure fault that in the Onan manual it simply said " call Onan for technical support" or something like that.  After calling Onan, it turned out that our Xantrex inverter was sensing that that the Onan was running at what it thought was the wrong time so the Xantrex sent a command to the Onan to shutdown.    Called Xantrex and they discovered that there was a known Xantrex software issue with their inverters from 2004-2006, and it would require a "simple" Xantrex re-flash of its software.

Getting the Xantrex re-flashed back then was a goat-rope in itself, but that re-flash ultimately fixed our Onan starting (anytime) & running issue with the coach running.

[jeffprupis]

Good stuff. Started recently, ran ok when we first got the coach. Thanks will check fault codes.

[Larry Moore]

I will chime in here, as we have the same issue.  If you start the gen first, put on a load such as an air conditioner, then start the engine ---
all works as it should.

Larry/Bev Moore
2005 Beaver Monterey Laguna IV

[Bryan Schmidt]

Larry,

You might have just explained why we would only have a limited success rate (1 in 4 times or so) in keeping the gen running after starting the engine.  I never thought to intentionally load up the gen before starting the coach engine..  Maybe the times our gen did keep running happened to have something like the inverter/battery charger kick in to apply its gen load before I would start the coach and that would be just enough load to make the inverter happy.

I never did get a full explanation from Xantrex techs as to what the re-flash of the RS2000 inverter actually fixed in order not to issue the Onan Gen shutdown if the coach engine was running first..

Did you remember if you read that in one of the user manuals or did you develop that working scenario yourself?   Either way, Thanks for sharing ....

[jeffprupis]

I will chime in here, as we have the same issue.  If you start the gen first, put on a load such as an air conditioner, then start the engine ---
all works as it should.

Larry/Bev Moore
2005 Beaver Monterey Laguna IV

Well I'll be - worked like a charm. Now is that a permeant fix or do I need to go through that sequence anytime I want to run the generator and the coach while driving?

[Michael Hannan]

I'm probably going to end up feeling foolish for ask this but what is the purpose of having the gen running while driving?  Aren't the house batteries charged while the engine is running and 110 will work from the house batteries through the inverter?  Except for coach AC.

MJ

[Larry Moore]

Bryan

I wish I could claim that I studied the issue and came up with the answer, but as on this forum most of the solutions come from sharing.
The gen startup sequence came from the original owner of the coach after the dealer could not find any other solution to the problem. Now that we know about the Zantrex inverter software bug, that would explain the need for our workaround.

Glad to be of help!

[Larry Moore]

Jeff

I still have occasions where the Gen will start and run when driving, but if it does not stay running, then I have to stop the engine and start the gen with a load (Hydro Hot electric will do) before a restart of the engine.

Hope this helps!

[jeffprupis]

It does thanks. On my way to Onan Service Center today for quick diagnostic, but if solution too much $$$ your work around will be my solution going forward. Thanks for the share.

For Michael (MJ) Hannan running AC while driving is EXACTLY reason. In high summer the dash ac is insufficient to cool the coach.