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-   -   12v Malibu outdoor lighting (https://www.askmehelpdesk.com/showthread.php?t=388173)

  • Aug 18, 2009, 12:55 PM
    ballengerb1
    12v Malibu outdoor lighting
    I can't believe I am being humbled by this simple low voltage outdoor lighting system but I am. Spent hours on a job that should be minute. Transformer is on as well as other lights. This one light tests good for voltage to the fixture before connecting the fixture. When I connect the 2 wires I get no voltage even right at that connection point. If I pull the halogen bulb out of the socket I test low voltage at both the connection and the socket. Installed another identical fixture, same problem. Bulb tests good. What the heck am I missing guys??

    Thanks,
    Bob
  • Aug 18, 2009, 01:01 PM
    tkrussell
    Sounds like a short. But there should be a fuse to blow on the 12 volt side.

    Could be a series circuit? With a short?

    Really need a diagram of connections, pictures if possible, check the transformer for 12 volt output? And that goes to zero when you connect a fixture?
  • Aug 18, 2009, 01:10 PM
    ballengerb1

    This is a series of lights and all other lights are working up to this one bad fixture. With no bulb pushed into the socket I get a good test for voltage by inserting my 2 test leads into the small socket. If I plug a bulb into the socket it does not light and there is no voltage at the slice, other lights do not dim or flicker. It is as if the bulb becomes the short but I tried 3 known bulbs and the same problem, voltage disappears and no light. I am thinking I will just start by replacing the main feeder line that runs down along this wooden walkway. I installed this for the HO 5 years ago and periodically have done repairs, never had a problem like this. I am sure any short would cause the other bulbs to dim or go out all together, no fuse that I know of with a Malibu transformer.
  • Aug 19, 2009, 04:03 AM
    tkrussell
    Yea looks like Malibu transformers do not have a fuse for the low voltage circuit. If the problem is that one fixture, could be a bad socket or wiring in trhe fixture. Corrosion could be acting as a high resistance short, just right to not trip the breaker, transformer thinks it is a load, maybe too much load, causing the voltage to dip to zero.

    Maybe just need a replacment fixture? Sounds like all the others work fine.

    Seems the transformers are rated for a certain amount of lamps, the instructions explain to be sure to relamp burnouts quickly as if left alone the other lamps will fail due to high voltage.

    http://www.malibulights.com/PDF/158ml12895.pdf
  • Aug 19, 2009, 05:35 AM
    ballengerb1

    I decided to tear everything up and run a new main line to all the fixtures. When I opened the little black box connector I found the problem. Malibus use a box with small pins to connect the wires rather than a thumb nut. These tiny little pins are supposed to pierce the insulation and make contact with the wire inside. The first connector pin just barely touched the wire, enough for me to get a reading. Once A load was put on the line the poor connection apparently broke. Threw the box away and used thumb nuts and all lights are now working. Thanks
  • Aug 19, 2009, 05:45 AM
    tkrussell

    Yea, that piercing probe connection method is popular with these light kits, and are often a problem.

    Good luck, now you can find your way home.
  • Aug 19, 2009, 09:49 AM
    ballengerb1

    Thanks, you are the only one who gave this a shot.
  • Aug 19, 2009, 01:45 PM
    tkrussell
    Hey no problem, must mean I got time on my hands. Right place right time.

    Hopefully everyone is busy enjoying summer.

    It finally arrived here in Maine. Even global warming is afraid of Maine weather.

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