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DouglasC's avatar
DouglasC
Explorer
Mar 21, 2021

Dead Onan 4000 generator

Went to fire up my Onan 4000 generator for the 1st time this year. Held the Start/Prime switch down on Prime and the light came on and flashed like usual. After about 5 seconds I released the switch as usual and pushed the Start side of the switch. Nothing happened - - totally dead. Tried the Prime side of switch again - - nothing happened. Last time this happened (generator dead) 7 years ago the cause was a faulty circuit board that needed to be replaced.

Anything else I should be checking before I order a new circuit board?
  • DouglasC's avatar
    DouglasC
    Explorer
    Mar 21, 2021
    Apparently I do have 12 VDC at the generator because the light came on when I 1st went to Prime the generator. But I will definitely check to make sure that there is 12VDC at the generator before I order a new circuit board.

    I just reconnected all the battery cables to the coach batteries before attempting to start the generator so the connections are all clean.
  • madjack60's avatar
    madjack60
    Explorer
    Mar 21, 2021
    I had the same problem with my onan 6500. I cleaned the battery cable connection at the battery and all was good. What threw me off is all the coach lights worked but the gen was dead.

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