How do I test a car stereo with a multimeter?

Discussion in 'Audio/Video & Home Theater' started by Oifish, Jan 3, 2011.

  1. Oifish

    Oifish Senior member

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    I know this isn't a car audio forum but you all are very intelligent and have helped me a lot in in the past. I hit a pot hole a couple days ago and my car stereo shut off. It's a simple JVC unit that I put in a couple years back so I can use my iPod while driving. I tested the wiring harness and every connection showed a resistance of .04ohms which is great, so I know my harness is wired correctly. However I'm not sure how to test and see if the JVC unit is receiving any juice or if there is a short in the ground. Thanks for any help.

    Admin: If this is in the wrong forum please move it to the correct location.
     
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  3. Number1

    Number1 Diamond Member

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    1 Check the fuse in the 12V line connected to the back of the radio. Check that you have power on the line with a voltmeter.

    2 Make sure the power conector is seated properly.
     
  4. Oifish

    Oifish Senior member

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    Fuse is intact and everything is seated correctly. To test the 12v line I would attach the red lead of the voltmeter to the 12v line, but what does the black attach to? The ground or the fuse in the fuse panel of the car?
     
  5. Smoove910

    Smoove910 Golden Member

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    Never, ever hook a ground up to a fuse block... bad idea
     
  6. Number1

    Number1 Diamond Member

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    How do you know the fuse is intact? Dd you measure it?


    Red on the 12 V

    Black on the car frame (ground)
     
  7. Modelworks

    Modelworks Lifer

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    Expect the 12v to read around 13.8VDC which is normal. If it is 12VDC you got problems bigger than the radio.
    Black to car frame 95% of the time . Some newer models have isolated grounds on the frame, in that case if you don't get a reading then attach it directly to the black wire on the power connector.

    Also some radios have fuses located on the back of the radio in slots. Check for fuses there or in the harness and also in the cars main fuse block.
    [​IMG]
     
    #6 Modelworks, Jan 3, 2011
    Last edited: Jan 3, 2011
  8. Oifish

    Oifish Senior member

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    Measured the 15A fuse in the back of the stereo and it read .04ohms. Measured the 12v line and it read 14.8v. So I'm guessing my stereo is the culprit not the wiring...