Troubleshooting an Onan 8500 in a 2012 Itasca Meridian 42E

[Owen Bridgeman]

I had trouble getting the generator to start this morning. Been starting it every week to 10 days while it’s stored. I was trying to make sure everything is working as we’re getting ready to leave. At first it would start then die immediately. Checked oil level and coolant level all okay. Manual said to shut everything off and start over. Generator fired up and was running fine lights changed over from coach batteries refrigerator came on and about 5 minutes later generator died. AC never turned on. Am I missing some simple step? There should be plenty of power to run both AC units? Call me confused.

 

[Morich]

If not thought about, there is one common thing on Rv that may be tripping you! How is the fuel supply as motorhomes are usually designed to not let us run the fuel to drive out by using the generator, so they stop at near 1/4 tank left?

 

[Morich]

If you get beyond the lack of fuel questions, this manual looks like it might be a big help and certainly knows far more about the game than I will ever know!

https://www.flightsystems.com/pdf/onan-rv-troubleshooting-guide.pdf

Lots of small points to look up like serial number and such but possibly a good spot to start?
Wish you luck but have to admit that is not my field at all as I had brothers for those problems!

 

[DNC-WO]

I agree with Morich; it sounds like fuel starvation. In had an Onan 6000 diesel generator on my previous motorhome that began exhibiting fuel starvation and it was the fuel filter. Changed the filter and fixed it.

 

[jerichorick]

I had trouble getting the generator to start this morning. Been starting it every week to 10 days while it’s stored. I was trying to make sure everything is working as we’re getting ready to leave. At first it would start then die immediately. Checked oil level and coolant level all okay. Manual said to shut everything off and start over. Generator fired up and was running fine lights changed over from coach batteries refrigerator came on and about 5 minutes later generator died. AC never turned on. Am I missing some simple step? There should be plenty of power to run both AC units? Call me confused.

Were you able to start it again? The question about your fuel tank level is the first step. Next, when did you do your last maintenance? Is your oil and water level good? How new is your air filter? What is the charge rate of your inverter set at? It must be lowered to about 10A when on generator. You only have 35A per leg to work with. Shore to generator is 100A to 70A respectively.

 

[RayIN]

An aside, Cummins/Onan opertors manuals state to run once a month for 2 hrs minimum at 50% load, otherwise it allows moisture to condense in the actual generator works.
Have you got the fuel filter replaced yet? What is your fuel tank level?
You can download the operator and service manuals for your Onan genset here: ONAN PDF MANUAL Links
or here: https://www.cummins.com/en-na/generators/rv-generators/rv-generator-manuals