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jimh406's avatar
jimh406
Explorer III
Jul 06, 2019

Onan 2500 LP won’t turn over no light on remote switch

My Onan 2500 LP on my 2005 built Host no longer will try to start and there is no light on the remote switch.. We ran it a few times on the last trip, and it seemed to work fine. On the last almost start, my wife was pressing the start button inside and after beginning to start, it went quiet. After that time, the light on the switch won’t light up, and the switch on the generator won’t cause any noise to happen and no attempt to start.

I’ve checked the 5 amp fuse. It looks fine, and I’ve also tried replacing the 5 amp fuse.

We are back home now, so what should I check? My first guess is the remote switch since it doesn’t even light up.
  • Finally got to check it out again. But, I tried the switch and it worked fine. Sounds like something is loose or the ground is off, etc. I’m not sure how to determine if it is fixed or not, otherwise. :(
  • Thanks for the suggestions. No, I don’t have a service manual. The manual that came with it has some troubleshooting steps, but assumes something is happening.

    I have a multimeter, so I’ll see where I’m getting power or not. Hopefully, today. I have other projects in front of it.

    Nothing happens when I press the switch on the generator.
  • What about the start switch on the generator itself? What happens when you use that?
  • It does nothing using the switch on the genset? I would start at battery connections.
  • by your description I'm guessing it's a loose or burned connection somewhere in line with the start switch. Start at the battery and make sure everything is tight.
    Do you have a multimeter that you can use to see if you are getting battery power at the fuse or on either side of the switch?
  • Download a copy of the "Flight Systems Onan Generator Troubleshooting Guide" and print it up. Also, do you have a copy of the service manual? They also have good troubleshooters. But start with connections and battery voltage as Sidecar suggested.
  • Sounds like you aren't getting 12 V power to the generator.
    You need a voltmeter to find out why.
    Do other 12 V devices still work ?