Onan Generators

[John Grant]

Hi group ,
Is there a specific section for onan generator troubleshooting etc ? I have one that’s acting funky.
If there a specific area can you direct me ? Thanks in advance!

[brobox]

Is that a 10,000? What is "funky". I didn't see that in the owners manual. Section 6 is troubleshooting
https://www.norwall.com/product_pdfs...g_opm_2015.pdf

[John Grant]

Originally Posted by brobox

Is that a 10,000? What is "funky". I didn't see that in the owners manual. [emoji3] Section 6 is troubleshooting
https://www.norwall.com/product_pdfs...g_opm_2015.pdf

Yes it’s a 10k, runs for an hour and shuts off with the usual code 36 fault.
I’m on the road in a small town and can’t locate a fuel filter for it so i took it off along with the air filter and cleaned both best I could. That didn’t make any difference.
After it shuts off, if I try to restart it sounds like it’s out of fuel.
I have 3/4 of a tank in my coach. The trouble shooting section isn’t much help.

[lwmcguire]

Fuel filter is the same as the old GM v8 diesel engines cars and trucks, so easy to find

[John Grant]

Originally Posted by lwmcguire

Fuel filter is the same as the old GM v8 diesel engines cars and trucks, so easy to find

Tried that , no one locally had it in stock that had the correct fittings [emoji18]

[John Grant]

Originally Posted by John Grant

Tried that , no one locally had it in stock that had the correct fittings [emoji18]

There’s many variations of the old style filters, mine looks like this and I can’t get anything to match this one.

Mine has an inlet and outlet catty corner to each other and the mounting stud in the middle. Below is a better photo.

[brobox]

John how many hours on the Generator?

Also the earlier models were reported here to have had a lot of fuel pump problems.
http://www.irv2.com/forums/f278/chan...ef-325105.html


Also an Amazon link with 2 days shipping https://www.amazon.com/dp/B019QH3FYK..._NxvJyb1JPVCP6

[jmorse1]

Any NAPA should have it...part# 3063

[Jburklo]

Originally Posted by John Grant

Hi group ,
Is there a specific section for onan generator troubleshooting etc ? I have one that’s acting funky.
If there a specific area can you direct me ? Thanks in advance!

Where are you located? Maybe someone on here is close by.

[jestal]

My gen did exactly the same thing intermittently for months. I replaced the fuel pump and fuel filter multiple times with no long term success. With a 12 volt test light on the fuel pump hot lead I finally caught the SOB stalling and discovered the voltage to the pump was disappearing.


It was hard to prove because the 12 volts was there without the load of the pump. I thought maybe the pump was pulling down the voltage but no.



Long story short: The electronic control board for the generator supplies the current to the pump directly and the board was failing causing the loss of 12 volts. It would still supply 12 volts but no amps with the load of the pump. Disconnect the pump and the test light would come back on.


The problem was temperature sensitive. When the board got hot it would loose the current to the fuel pump.



In your situation it is relatively easy to see if this is possibly a problem. When you pull the fuel filter thru the access panel on the left side you can find the hot lead to the fuel pump. Jump it directly to a good 12 volt supply and see if the gen begins to run fine.


The house battery terminal block is on the left front frame rail which is a convenient 12 volt source. I rigged a fused jumper with alligator clips and powered the fuel pump directly. The gen ran perfectly from that point on as long as the jumper was in place!


I ended up replacing the control board in the generator but still carry the jumper "kit" inside the generator case so I can force feed the pump 12volts if the board dies again.


This was such an intermittent problem I cannot tell you how frustrating it was to pin down although a number of Onan techs have confirmed the relatively high failure rate of the control board. Most of the time devices like this are fed a fused 12 volts and the PCM will pull the pump to ground to make it run. I have never seen a PCM provide the 12 volts directly like the Onan does.


The other PIA is that the board for the Onan is about $850 so you want to be sure before just buying a board.



Good luck!

[Gary.Jones]

Nice catch AL !!!!

Gonna copy that and save it away in my "I may need to know this...." series of files.

Gary

[John Grant]

Originally Posted by Gary.Jones

Nice catch AL !!!!



Gonna copy that and save it away in my "I may need to know this...." series of files.



Gary

Great information all, thank you so much. I’ve located a new fuel filter this morning and will install that. If that doesn’t solve the issue I’ll try jumping the fuel pump.
Wish me luck!!

[John Grant]

Originally Posted by John Grant

Great information all, thank you so much. I’ve located a new fuel filter this morning and will install that. If that doesn’t solve the issue I’ll try jumping the fuel pump.
Wish me luck!!

Update:
The new fuel filter did not solve my issues, generator runs consistently for about an hour and then throws a fault 36 code.

There was mention of jumping the fuel pump earlier, all I can see is the injection pump with no wires attached to it. Is there another pump for the Generator somewhere?

2013 Aspire QD 10k

I’ll be passing through Atlanta next week, do y’all think it’s worth stopping at NIRVC and let them take a look ?

Note: after the generator sits for a while and I prime it, it will run for another hour usually. This has me scratching my head.

[lwmcguire]

Originally Posted by jmorse1

Any NAPA should have it...part# 3063

Exactly, old GM diesel filter
Works on 10 and 12.5k