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Bird_Freak's avatar
Bird_Freak
Explorer II
Mar 09, 2016

A little generator help

Need a little info guys.
My neighbor just got a older class A with a Onan 5000. He says it starts and instantly dies. He has by passed fuel pump, replaced filter and plugs. He ran out of ideas so I took a look and as soon as you take your finger off start button it kills ignition. I bypassed low oil switch and it made no change. I need suggestions.

28 Replies

  • Matt_Colie wrote:
    Eddie,

    Knowing the actual model of the Onan would help, but there are two things that could do as you describe (expecting that the facts as presented are accurate).
    First is that most of the Onans use the flyeheel alternator to provide the run signal that says its cookin'. If this is open (not uncommon) or just a bad connection the control board doesn't know it is running or at least should be....
    Second is a control board issue. Without knowing the model so I can look it up all I can tell you is that replacements are dear. Onan is so proud of those boards.

    Matt
    That's what I am thinking Matt. it will be the weekend before I get back with him.
  • PatRenee wrote:
    Check the oil ... some have pressure sensor that will shut it down if low on oil...... it will crank then die if oil pressure doesn't build up...

    That was my immediate thought but, the OP bypassed the low oil switch.
  • Eddie,

    Knowing the actual model of the Onan would help, but there are two things that could do as you describe (expecting that the facts as presented are accurate).
    First is that most of the Onans use the flyeheel alternator to provide the run signal that says its cookin'. If this is open (not uncommon) or just a bad connection the control board doesn't know it is running or at least should be....
    Second is a control board issue. Without knowing the model so I can look it up all I can tell you is that replacements are dear. Onan is so proud of those boards.

    Matt
  • Check the oil ... some have pressure sensor that will shut it down if low on oil...... it will crank then die if oil pressure doesn't build up...
  • Mower gas tank mounted on a ladder above generator. Float bowl stays full.