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Radio noise

Discussion in 'Audio' started by Ross, Apr 19, 2001.

  1. Ross

    Ross Registered Member

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    When I use the radio, cd player or tapeplayer in my blazer there is a whineing noise. The noise gets louder as the trucks RPMs go up - - - dose any one know what I have to do to fix this.

    1986 K5
     
  2. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

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    Sounds a lot like a classic "ground loop" problem.

    Check the grounding of the stereo...if the ground wire(s) is/are corroded or loose, you can have these kinds of problems. How complex is the stereo? Clean up and tighten the grounding connections and try listening to it again.

    Do you have seperate power amps, etc? If so, it's a good idea to make sure that each of your components are grounded to a common point in the car.

    A lot of people will insist that the BEST way to wire a stereo is to run a ground wire directly back to the battery terminal....that is simply not true. In fact, if you already have "engine whine" coming through the stereo, it is very likely that it will get WORSE by wiring directly to the battery. [​IMG]

    If sound quality is not a major concern, you can always buy one of those "ground loop isolators" and wire it into your stereo. To be honest, it's probably MORE work to install one of those, than it would be to find the bad ground and fix it the right way.

    Just my $.02

    -Greg72
    [​IMG]
     
  3. '73 K5

    '73 K5 1/2 ton status

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    You might also want to check how the power/ground wires for the radio are ran. Do they come really close to any other high current wires? If so, move them around a bit. Otherwise just do what Greg72 said.

    '73 K5
    Chevy good...Ford bad
     
  4. zach78k5

    zach78k5 1/2 ton status

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    i had the worst case of this. if you have an amp make sure the preamp wires are run on the opposite side of the truck from the power to the amp and away from any other high current sources. use monster cable it helps a lot. cheap patch cords will let in a lot of noise. if this doesnt help use the common ground as was mentioned. if you have an amp your ground should be the same gauge wire as your power and should be no longer than 12 inches long. ground your stereo and any other stereo stuff to the same spot. the stereo ground can be long but not the amp. if this all fails go to circuit city and get a noise filter. this will go inline with the preamps. if you dont have an amp just check the players grounds, and the battery grounds. i even bought a second ground cable for the battery and grounded that in two spots. i had to use a noise filter in the end to totally do away with the noise.
     
  5. Gandolf

    Gandolf 1/2 ton status

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    The whine you are getting is probably from the alternator. I was also getting the whine, that increased with RPM, in my CD Receiver. When my alternator failed recently, I replaced it, and with the new one, the whine disappeared.
    There are filters you can get that will block the whine. I think Radio Shack sell them. Someone else might be able to tell you specifically what to get. Since my whine went away, I never dug any deeper for a solution.

    '89 K5 Silverado..."You can’t have a real adventure, unless the outcome is truly uncertain".
     
  6. MUD_SPEC

    MUD_SPEC Registered Member

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    This happens because there is a burnt diode in the alternator.
     
  7. DBLAZER

    DBLAZER 1/2 ton status

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    I love these posts. I get this phone call all the time at my shop. It is very very very hard to determine where noise is coming from. Everyone here is right. heh hehe heh!!!!

    [​IMG]
    http://autotronixcaraudio.com
     

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