Fridge not running on 12volt

Discussion in 'Fridges & Ovens' started by RobGriff, Mar 20, 2018.

  1. RobGriff

    RobGriff Funster

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    Hi my fridge will not work on 12volt only makes a buzzing noise. Runs great on 240 and gas any idea’ s please thanks Robert
     
  2. Bill_OR

    Bill_OR Funster

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    What sort of fridge? Mine will only run off 12v when engine is running.
     
  3. MikeD

    MikeD Funster

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    As above. 12v usually only works with the engine running
     
  4. RobGriff

    RobGriff Funster

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    Engine running and fridge will not work only a buzzing noise from fridge
     
  5. pappajohn

    pappajohn Funster Life Member

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    How do you know it's not working.
    In 12v operation there is very little heat from the vent, if any, and no noise at all.
    12v will not cool the fridge, it will only maintain a temperature already present from gas or 230v.
     
  6. RobGriff

    RobGriff Funster

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    Fridge works well on other services 240/gas but will not work on 12v when engine is running
     
  7. mitzimad

    mitzimad Funster

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    you need to find out if theres a 12v supply to the fridge when the engine is running if theres not it could be the relay
     
  8. RobGriff

    RobGriff Funster

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    No just a loud buzzing coming from the fridge pappajohn too noisy to travel with
     
  9. pappajohn

    pappajohn Funster Life Member

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    Time to get it checked.
    There should be no noise at all on 12v never mind noise that can be heard over the engine.
     
  10. RobGriff

    RobGriff Funster

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    Hi Steve thought it might be the relay ,going to have a look tomorrow after work . Hope you and Diane are keeping well . Rob and Deb
     
  11. RobGriff

    RobGriff Funster

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    Thank you pappajohn going to have a look tomorrow after work
     
  12. Spanner

    Spanner Funster

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    Can't help with the noise but when our Thetford fridge stopped working on 12 volts it was due to a bad electrical connection at the plug and socket found at the rear of the fridge at floor level in our case easily accessible from the lower vent cover, pull the connector apart and look for a burnt connection.
     
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  13. mitzimad

    mitzimad Funster

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    actually the buzzing does point towards a relay not holding follow the buzzing noise to locate it mine is behind the fridge
     
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  14. jockaneezer

    jockaneezer Funster

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    I've just recently deleted the couple of pics on my phone that I took of the 12 volt electrical connections on the rear of my Dometic and I seem to remember seeing an automotive relay in amongst it all. If that's playing up, it will make a buzzing noise. Usual reasons for it to buzz are low voltage supply to the coil or a bad connection. I've had to replace a couple of corroded Lucar connectors on mine.
     
  15. autorouter

    autorouter Funster

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    There are two 12V supplies to the fridge. One is a low-current supply to power the control board. The other is a high-current supply (about 14 amps) that powers the heater element that works the cooling.

    The low-current one is on all the time. The high-current one is selected by the manual or auto selection. On most British MHs you can not run on 12 volts unless the engine is running, and this is done using a relay.

    Has this problem suddenly started after working OK for some time? I ask this because if it's always been like this, or the wiring has been changed or is incorrect, the relay could be wired wrong, so that it switches itself on and off rapidly, making a loud buzzing sound.
     
  16. Taff Thomas

    Taff Thomas Funster

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    Funnily enough I have this problem on the motorhome I have just bought (second hand.) I will post more detail when I pick it up.
     
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