cummins/onan genset issues - FIXED

Sorry to hear you are having so much trouble. Mine has been trouble free for almost 12 years now. It's an 8,000 and I've used it quite a bit.
Sounds like a battery connection to the starter or ground. Maybe a mobil tech can help you.

The genset in our old MH never had an issue. I've had issues with 3 in 3 years with this one.

I have had many problems with genset as well. I agree with you about reliability mine is a gas engine not diesel. Has cost a fortune over the years to keep it going. I am wondering if Honda would be a better choice for Mo Ho builders to install.

My Onan 5500 has been very finicky over the years. Have had more problems with it than anything else on the mh.

In the 5 Class'A' MoHOs we've had, never had any Genny problems. Our present one is a 4000 like u'rs. No problems yet. I wonder if the dealer you've dealt with for u'r 'Warranty' problems is 'Fixing' u'rs with "Used, but Good" parts?

Effy wrote:
Gen won't start. No idea why. It's a 4000. Started and ran fine a month ago when we took our last trip. Went to start today and nothing. A clicking almost like the batts are dead - they aren't , full charge. It sounds almost like it does when it's priming. Maybe I over primed? But no crank at all.

Never had any issue with the RV itself, but this genset has been nothing but problems and probably the most unreliable piece of equipment I ever owned. The first gen set froze up and broke the shaft the first month we had it. It had to be replaced. Second genset fried a board getting ready for a trip. Had that replaced. Thank goodness all under warranty. Now this one plain won't start. Like I said, ran fine a month ago.

This is the kind of stuff that makes me want to give up Rving altogether. I mean you pay money in the hopes of having something reliable and it continues to fail. I used to think Cummins was a good brand. Since they bought onan I hear nothing but problems. My generac at the house is as reliable as anything I have ever owned. This cummins/onan is garbage.

I feel the pain. I think RV's were actually better in the 1980's than today. However, that doesn't solve your problem. If it is still under warranty, then USE it!!!! :) I do feel your pain though.

Shouldn't be too hard to watch the battery voltage at the battery terminals and have someone crank the GENSET. If you do see bad negative DC VOLTAGE drops with your meter touching the center of the battery terminal posts then the battery is at fault. If you don't see drastic jumps in the negative direction here then go read the voltage right at the GENSET and do the same thing again. If it jumps way down in DC VOLTAGE which is causing the clicks only then you have a bad connection between the GENSET and the battery terminals...

Keep in mind your battery will show a voltage drop but it should not be going down below 12.0VDC or so when the starter is pulling DC current. My batteries drop down real quick to around 12.3-4VDC when hit with a very large load and then jump right back up to its full charge of 12.6-7VDC when I remove the large load. When you would see DC VOLTAGE dropping way below the 12.0VDC reading is where it will start making clicky sounds like it does when your battery is dead.

The battery cables around the terminal could be at fault or any number of connection points down the line.

The GENSET will draw a whole bunch of DC CURRENT when trying to start starting and will find all of these weak connection points very quickly...

It could even be the GENSET starter motor contacts making bad connections but that probably would not show up in your DC VOLTAGE readings...

Another quick test is to nose up your truck to the GENSET and use JUMPER CABLEs from the truck start battery clipped into the GENSET DC Connection terminals and see what happens.

Once you develop an easy to understand test procedure then you can identify where things along the long leads between the battery terminals and the GENSET are going bad for you... It will go much better for you then knowing what to look at when this happens...

Just my thoughts
Roy Ken

Just one click? Or a series of clicks?

With "clicking" check the batteries under load, ie trying to start gen. If OK at the batteries and at the gen DC input then it's likely the starter or solenoid.

I have a Onan 2003 8K diesel gen in my 2003 MH with 675 hrs. and no problems. I do all recommended maintenance and run it monthly as required. Mine has been very dependable.