Generator Problem

Chuck.N

Senior Member
Joined
Jun 7, 2020
Messages
162
We've been on the road for about 3 weeks now, and last week developed a problem with the generator (Onan QG5500). It has worked just fine until the last 7-10 days. It has less than 50 hours on it.

1. The generator will not start at all from the One Control panel. When pressing start, it immediately pops back into the Off position. This used to work just fine.

2. The gennie will start from its front panel, but will only run for about 10 seconds, and then it shuts down. I can watch the fuel control arm move up like it's trying to flood itself to stop. No manual manipulation affects this. Unfortunately, it is not throwing a code. This happens whether the load circuit breakers are open or closed.

I was thinking it's a fuel issue, but now I'm not so sure. With the One Control acting so strange, I'm thinking perhaps the starting circuit relay from One Control is latched in the Off state. Somehow the generator manual start senses this, and it shuts down. I can hear the unit priming when manually starting, and the fact it starts and runs, even for 10 seconds, tells me I have air, spark, and fuel.

I have powered down the One Control touchscreen, hoping that will reset the relays, but no joy. The touchscreen and App work fine for everything else.

Has anyone else ever encountered something like this? Does anyone happen to know where the Gen start relay is located in the M399th? I've reached out to the nearest dealer, about 2 hours away, but have not yet heard back. We're full timing now, and this is really putting a kink in our plans.

TIA for any advice!
 
A couple of things come to mind here...1. Check your oil level in the generator engine to make sure it is not low. I suspect this would trigger an alarm if it was, but I don't know that for sure. I do know it will shut the generator down if it is low....just not 100% sure about an alarm for that. 2. It seems I read somewhere that the pickup tube in the tank does not go all the way to the bottom of the tank. If that is true, your tank may be at a level that is just too low for the generator to continue to run. 3. Open up the generator icon on the One Control and make sure that the "Quiet hours" time is not set to a time that the generator will not run. Those times can be changed to whatever time you want, and maybe it is set incorrectly. If I remember correctly, there is also a switch to turn that function (quiet time) off in the One Control on that screen. If you don't need that function, turn it off.

Hopefully this will help you do some more checking for things that may be contributing to your issue.

Edit.....Again, if I'm not mistaken, the starter relay is located in the generator itself behind the removable front cover. You should be able to follow the heavy RED cable to it.
 
Thanks for the quick reply.

Ya'll are going to love this! There was a mobile tech working in the park today on some other coaches. I had spoken to him briefly about this problem, and another separate issue, and he stopped by late today to take a look.

No sooner did he step on the coach and I went to show him the problem on the One Control, and sure as God made little green apples, it started right up. I swear, it was the strangest thing ever.

We don't know what the original problem was, but we exercised it half a dozen times before he took off, and it worked like a champ.
 
Glad to hear it works. The generator control module should be behind the false wall in the basement if you need to get to it at some other point.

Sent from my SM-G950U using Tapatalk
 
Glad to hear it works. The generator control module should be behind the false wall in the basement if you need to get to it at some other point.

Sent from my SM-G950U using Tapatalk

Good to know! I'm sure eventually I'll need to get back in there.

I was going to drop you another email about this, but thought I'd give you a break for a day.😁
 
Just for clarification, it's no longer a separate controller. It's built on to the the main controller. The only separate controller I have found is for the Schwintek controller.
 
Just for clarification, it's no longer a separate controller. It's built on to the the main controller. The only separate controller I have found is for the Schwintek controller.
Good to know. I'm only going off what I had in my 2017. I suspect the main controller is still in the same area.

Sent from my SM-G950U using Tapatalk
 
If you take the basement wall off directly behind the interior stairs, that's where it is on my 351M. Basically, it's mounted the stair framing for the lack of a better description.
 
If you take the basement wall off directly behind the interior stairs, that's where it is on my 351M. Basically, it's mounted the stair framing for the lack of a better description.

Hmm, that's different for sure. My 2018 Momentum 394M has four different modules back there...under the steps in the basement area. One is the LCI Multi-Output LED Lighting Control Module, one is a General purpose module, one is for the Tank monitoring and water pump control, and the last one is the Generator Genie module.
 
This what the "new" module looks like.

image_5782.jpg
 

Wow.....I think I would prefer (not that we get a choice on the matter) to have 4 individual controllers/modules. I checked price, just our of curiosity on the LCI Multi-Output LED Controller and it, by itself was almost $500. I can't imagine what the cost of the "all in one" module would be if a portion of it quit working and there are likely NO serviceable user parts inside. Just WOW!
 
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