Grounding issue (?) in old solid body guitar

Discussion in 'Luthier's Guitar & Bass Technical Discussion' started by slidincharlie, Feb 22, 2009.

  1. slidincharlie

    slidincharlie Member

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    I have an old MIJ strat-like guitar (maybe a Kawai?). It's a 3-pickup model with one volume, one tone and three slide switches to turn each pickup on or off.
    Sure it needs some work in the electronics (faulty connections, etc.).
    I opened it and found a floating wire starting from the volume pot's back (ground) and going towards the slide switches area... but it is disconnected. Where did it go? Maybe to the metal case (=ground) of one of the slide switches? Do such switches need to be grounded? Currently neither the pickups nor the slide switches are grounded actually...
    I attach a picture of the guitar's guts.
    TIA
    [​IMG]
     
  2. Keyser Soze

    Keyser Soze Member

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    WAG says at one point it went to the bridge to ground the strings.

    The slide switches should be in contact with the shielding, which is in contact with the pot cases, so there would be no benefit to an additional ground wire (as an added loop it would more likely be a source of noise.)

    Absent an obvious reason for its presence I'd get rid of it.
     
  3. slidincharlie

    slidincharlie Member

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    Fact is that the pickups cases are in contact with the switches cases, but the switches are not in contact with a pot case. If I solder the floating wire (red arrow in the picture above) to e.g. a switch case, I'll have pickup cases and switch cases grounded , won't I? Remember that the floating wire starts from a pot case.
    --Carlo
     
  4. Keyser Soze

    Keyser Soze Member

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    Odd. Is there some sort of spacer or bushing that is preventing the pots from physically contacting that shielding foil? Ideally all of those cases and the shielding should be connected. As a principle it is best to have ground connections be as short as possible, but if nothing else then yes you should reconnect that grounding wire.
     
  5. slidincharlie

    slidincharlie Member

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    You're right.
    Actually the pickups are grounded through the aluminum foil, but this foil is a home made shielding that does not work very well. I'll make a better shielding with adhesive copper foil, so the floating wire most probably can be eliminated. That wire is likely a remnant of the original circuit, which was without aluminum shield.
    Thanks for clarifying the issue. :)
    --Carlo
     

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