2008 Fleetwood Bayside 12V when plugged in, no 12V DC on battery

Discussion in 'Wiring' started by John Hill, Jun 19, 2019.

  1. John Hill

    John Hill New Member

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    Jun 19, 2019
    New Brunswick
    The 12V system won't work off the battery. When plugged in to 110V, the interior lights and everything 12V works, so the converter must work. The battery has 12.56V (when not plugged in). I checked the battery voltage going into the converter, 12.56. Voltage at the top fuse (15A) is 12.56. There is no voltage at the other 15 and 20 amp fuses. I checked the switch that cuts the power when the trailer is down (it's under the swing sink on this model). It is only reading 0.21 volts. My best guess is a poor ground connection somewhere, but why does it work through the converter? Why is there no voltage to the other fuses? Any ideas?
  2. pej

    pej Member

    Likes Received:
    Jul 17, 2013
    What brand and model of converter do you have? There could be another fuse that you are missing. There may be a weak ground connection allowing you to get a meter reading but not pass current. The battery is typically grounded to the frame up front while the white return wires are grounded to the frame near the converter. Run a temporary wire from the white wires directly back to the battery's negative post or just clean up both ground points.
    Try disconnecting the battery, plug the trailer into AC. Then measure the voltage at the converter and then at the battery connection wires. These readings should be the same.
  3. Raycfe

    Raycfe Waterford Ct.

    Likes Received:
    Oct 3, 2007
    Waterford, Ct
    The first thing I would check is the battery protection fuse. Usually 20 amp mounted in the Convertor. If the battery cables get installed backwards this will blow. No power from battery ....start at the battery, battery connections and fuse. Your most likely have a small box inline with the positive battery cable, could also be a fuse but most likely an auto resetting circuit breaker. If their connections are all rusty, remove it and that it to an auto parts store to match up.. Usually also 20 amp.

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