Forum Discussion

stepside454's avatar
stepside454
Explorer
Aug 09, 2015

Onan marquis 5500

I discovered the Onan 5500 in my MH wont start recently. the fuel pump is not getting any power to it. I checked the fuse, its good, I have to assume its either the fuel pump relay or the control board has gone bad. has anyone else here run into this ? ive been looking online for a part# & price for the relay . but cannot find.
  • Gjac's avatar
    Gjac
    Explorer III
    j-d wrote:
    I have not personally used Flight Systems but despite their unlikely name they have genset information and components. A number of us have found them helpful.
    They were a big help to me in fixing my Kohler generator. They will rebuild Onan boards(non potted ) a lot cheaper than buying a new one. Even sent me a service manual for the genset.
  • on the 5500 there is a PRIME position on the start/stop switch, push and hold the STOP/PRIME button down and listen for the pump to start clicking, this will indicate that the pump is pumping and will soon prime itself. When the clicking stops or slows down, let go of the switch and press the START BUTTON. should start after 15 to 30 seconds. Just a suggestion. But back to your question, have you actually used a volt meter while trying to start the genset to determine that you have no voltage? could be that you lost your prime and if those 5500 sit ( 4 weeks or more) for a while the carb will go dry and you have to prime in order to start. Give it a try.
  • j-d's avatar
    j-d
    Explorer II
    I have not personally used Flight Systems but despite their unlikely name they have genset information and components. A number of us have found them helpful.
  • Try this place...

    www.partsfortechs.com/asapcart/generator-parts-onan-c-14_104.html