Frustrating Generator Problem

[Hikerdogs]

Earlier this year when we brought our 2001 Winnebago Adventurer out of storage I had a problem starting the generator. The generator is an Onan 5500 Marquis Gold model HGJAB. After a few tries it started and worked properly. After an hour or so it died and refused to start. Originally the display showed a code 32 (slow cranking prior to start). It seemed sort of strange since the batteries were fully charged and cranking speed was normal.
I went through the complete diagnostic tree associated with code 32 and found no problems. I reassembled everything and gave it a try. Once again it started and ran properly for about an hour. Just before I was going to declare victory and shut it down it died. This time the display showed a code 13. (under voltage for more than 5 seconds)
Again I went through the diagnostic tree including removing the brushes and cleaning the slip rings. Once again after completing the procedures it started and ran fine for about an hour. This time when it died a code 41 was displayed.
Again after going through the diagnostic tree the thing started and ran fine for about 15 minutes. Since then it died and retrned a code 45. After a restart it again died and returned the original code 32. Now it refuses to start and continues to return a code 32 even though it cranks at normal speeds.
I believe there is a problem with the control board but don't understand the different error code each time it dies. I'd like to be more certain before I spend $300.00+ for the part.
Has anyone had a similar problem? If so I'd appreciate any insight you have.

[RJay]

As I remember there is a summer/winter setting on the choke. Also it could be a sticking choke. The generator starts hard but once up to temperature the choke stays shut and the engine dies and will not start until it cools.

[wa8yxm]

I have seen code 31 from bad brushes.. I don't know the other codes so can't help you (And you checked the brushes so that's covered) Code 31 really means "I"m not generating any power" by the way.. that's how it tells if it's cranking fast enough, if it is, there is output.

[Bug512]

Maybe try a call to Onan and see if they have technical support?

1-800-888-6626

[Hikerdogs]

Thanks for the information. I've checked the choke, choke heater, linkage and throttle butterfly and all are operating properly. The brushes are in good shape and well over the minimum length of 7/16".

I've also been in touch with Onan and they're more than happy to connect me with the closest authorized dealer and parts distributor. I don't mind spending money at the dealer if there's a some assurance that the problem can be cured in a reasonable amount of time and at a reasonable cost.

Since the problem seems to manifest itself with a variety of fault codes I'm not confident that the mechanic won't be playing a parts replacement guessing game. My experience has been once a part is installed the customer owns it (and the labor to install it) regardless of whether or not it cures the problem. I'd rather avoid that scenario if at all possible.

[bad1032]

Had the same issue with a friends adventurer, it ended up being a bad fuel pump. same symptons as your is doing

[Bug512]

For future knowledge. Is it a separate fuel pump then the coaches engine ?

[Hikerdogs]

Quote:

Originally Posted by Bug512 For future knowledge. Is it a separate fuel pump then the coaches engine ?

For the record the generator has it's own fuel pump. It's a diaphram style one under the baseplate in the left front corner when facing the unit.

Thanks for the tip bad1032. I've repaced both fuel filters and cycled the pump with the line open. There was plenty of volume but I haven't yet done a pressure test.

[Bug512]

Thanks for the info.

[bad1032]

we had the same problem with his , would run and hour 2 hours then all of a sudden it would sputter then cut of and not restart, called onan for help and they said oil issue, oil to thin, changed it and same thing happened, we waited ofr it to cut off and then went and pulled the fuel line while cranking and not a drop of fuel pumoing, changed to a new pump and ran for 2 years be fore he traded it in on a phaeton

[ccook129]

I could scan you a copy of my service record if you want to see it,but here's a breakdown of what I had done.Replaced carb,brushes,fuel filter oil and filter,plugs.Code 32 bad pc board after I took it to cummins dealer,they put it on a bench hooked up breakout tool and replaced pc board fired right up took 3/4 hours to check and $343.12 for board $186.00 for labor they charged 2 hours labor for removeing and reinstall genset.Later found same board for $50 bucks less and I guess I would have installed it myself,just needed them to run the test with breakout tool,which is $96.00 bucks.So if you can have them test it and it comes back code 32 needs new control board buy your own it just plugs in,about $300.00 on ebay.

[ccook129]

Onan Generator Control Circuit Board 300-5374

[Hikerdogs]

Quote:

Originally Posted by bad1032 Had the same issue with a friends adventurer, it ended up being a bad fuel pump. same symptons as your is doing

I got a few minutes today to check the fuel pump. It puts out great volume and has plenty of pressure. At least that eliminates 1 possible cause for the problem. The next step is to slide the unit out of the compartment and check the connecting wiring harnesses

[NO1RAINH20]

Have replaced several of these fuel pumps that check good when cold but quit pumping when they build up some heat,and since it takes an hour to show up i would not be so quick to say pump is ok.