Onan 5500 Problems ???? Need Advice

[texas_craig]

I just purchased a 1999 Southwind with a Onan 5500 GenSet. The generator has been having a problem staying running. It would run for say a hour or so then just shut off. It would restart easily but would do the same thing later on. I have replaced the fuel filter and and checked the fuel pump and it appears to be working fine. I noticed that both batteries for the coach were completely shot and have replaced them with new ones. The generator was running when I disconnected the battery and it died immediately. Now the gen. is starting and running but the A/C will not come on. My question is why ?? Could the bad batteries that had corrosion on the terminals caused the gen. to shut down randomly ? And why now that its running, I don't have electricity ?? Any help would be greatly appreciated.

 

[Paul235]

RE: Onan 5500 Problems ???? Need Advice



One more item to check as possible causes for shut down is oil pressure switch. If generator sense low oil level, it will shut down at once. Might be oil related.

 

[texas_craig]

RE: Onan 5500 Problems ???? Need Advice

I looked into that but it doesn't appear to be the problem. But I will keep a eye on it . Thanks

 

[Kirk]

Re: Onan 5500 Problems ???? Need Advice

What Onan uses is a low oil shut-down but it will also frequently shut down if the oil it too high and that sounds like your first part of the problem. When the oil is too high it will slowly create foam and once foamy enough it will think it is low on oil and will shut down. Check to make sure that the level is between the low & high marks on the dip stick. Do not allow it to go at all above the high mark.

As to the battery causing some kind of problem, I'm not sure exactly why, but I have the same Onan as you and the same vintage. About a year ago mine also shut down when a battery failed. It had a shorted cell and once I removed the bad one it would run with just the good one. Since the Onan only puts out 120V-AC power, the only thing that I can think of which might cause the problem would be if it somehow effected the field power since an Onan will shut down if it does not supply 120V output.

 

[tims52]

RE: Onan 5500 Problems ???? Need Advice

Texas Craig, you might want to check inside the gen set enclosure, remove the outside cover and stick your hand inside( make sure the gen set is not running). Put your hand inside and all the way toan check around to see if you can feel anything.I had the same problem and found out the mice had made a nest near the cooling fan, I used a blow gun, too blow out the nest, an what a nest it was.

 

[texas_craig]

RE: Onan 5500 Problems ???? Need Advice

Thanks for all the advice. I installed new batteries and reset the breakers and it seems to be doing fine now.. Only time will tell if I fexed it or not.