Announcement

Collapse
No announcement yet.

Boot/trunk light not working

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Boot/trunk light not working

    Originally thought it was a blown bulb but having replaced it still dead. Removed the light and checked it direct from the battery and light works fine. Multimeter on the + and - and shows me with 12v. Pish in the switch and drops to pretty much zero, 0.01v, let the switch out and 12v returns.

    what am i missing i hate electrics
    sigpic

    1992 3b S2 Coupe

  • #2
    If you have good voltage at the bulb when switched on then you must have a poor earth.
    Nothelle S2 Avant in restoration

    Comment


    • #3
      And idea where the earth is for the light? Or is it more generalised bad earthing lol
      sigpic

      1992 3b S2 Coupe

      Comment


      • #4
        Originally posted by s2driveruk View Post
        And idea where the earth is for the light? Or is it more generalised bad earthing lol
        I'm not sure on the Coupe, I think its the same as mine. Earth wire will be brown, follow it back and you should find a connection to the body. Take that off and clean it up making sure you have a good contact. I cant remember if it shares its earth with the rear lights. I will see if I can find the relevant pics on my phone.
        Nothelle S2 Avant in restoration

        Comment


        • #5
          Very simple circuit.
          Power to one side of the bulb.
          The switch just goes to ground.
          So
          Either the feed won’t pass enough current to light the bulb or the switch won’t pass enough to ground it.
          Or there’s corrosion on the bulb holder.
          Try the same test but with the bulb in place.
          Measure from a ground point on the chassis to one side of the bulb then the other.
          Clean the bulb holder. W3
          Wiggle the switch. F5





          S2 Coupe 3B Project


          Ur quattro restoration

          S2 Avant

          Boost is the new rock and roll!
          sigpic

          Comment


          • #6
            Thanks..love the ‘very simple circuit’ i am a complete leccy ludite
            sigpic

            1992 3b S2 Coupe

            Comment


            • #7
              Bulb holder is very clean, no corrosion on either connector and spades look ok.
              sigpic

              1992 3b S2 Coupe

              Comment


              • #8
                Originally posted by s2driveruk View Post
                Thanks..love the ‘very simple circuit’ i am a complete leccy ludite
                It's just the far right line, top to bottom you are looking at. Top + to bottom - ground. Switch and bulb in the line
                Nothelle S2 Avant in restoration

                Comment


                • #9
                  It's possibly the loom going into the tailgate broken wires in the top left corner
                  Mike

                  http://www.s2-audi.co.uk

                  Comment


                  • #10
                    Thanks all, will pull the rubber boot off and see what i discover.
                    sigpic

                    1992 3b S2 Coupe

                    Comment


                    • #11
                      You can always just run a second earth wire in to confirm your suspicions its a bad earth.

                      Comment


                      • #12
                        What's T3r/3? Is that a connector in the loom?
                        91 Modded 3B
                        14 A6 Avant Black Edition

                        Comment


                        • #13
                          Is your new bulb LED?

                          Comment


                          • #14
                            Nope just an old school one
                            sigpic

                            1992 3b S2 Coupe

                            Comment


                            • #15
                              Originally posted by s2driveruk
                              Thanks..love the ‘very simple circuit’ i am a complete leccy ludite
                              Lol
                              Yeah it’s just this bit
                              12V at the top, chassis ground at the bottom


                              S2 Coupe 3B Project


                              Ur quattro restoration

                              S2 Avant

                              Boost is the new rock and roll!
                              sigpic

                              Comment

                              Working...
                              X