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booty51's avatar
booty51
Explorer
Jun 14, 2013

Onan Marquise 7000

Model#: 7NHMFA26105F
S/N: G963550726

We are on a trip and generator will run for several hours and fall off line. Shut down both ac units and restart generator let it power back up put ac units on and generator will shut down againafter about an hour. Repeat above start up proceedure this time generator
starts ,but we here both carbon dioxide and propane alarms chirp while restarting. Generator will run about an hour and shut down. Repeat restart proceedure again generator will not restart and both cabon dioxide alarm and propane alarm chirp while attempting to restart. Let generator sit over night and same thing the next day. This is an older generator so no codes. never heard detectors chirp when starting before. Coach is a 97 Allegro Bus gasoline.
things i have done to remedy problem.

Checked to make sure fuel pump runs.
Fuel solonoid opens and closes
blew compressed air thru small fuel supply line
replaced fuel filter.
fuel tank is over 50% full

any one have any ideas i am thinking it is not fuel related.
  • I had the exact same problem with 86 allegro with 6500KW Onan......I chased that problem for several years....and a hell-of -a lot of new parts.....I got the wiring diagram and figured out what it was......
    The low oil pressure sw would get hot relax and ground the ign.
    I couldn't get to it so I disconnected it.
    I would seriously think it was that or the overheat sensor which also grounds the ign. If its the overheat you need to find out why......but these switches get old and malfunction.