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Factory amp bypass necessary?

Discussion in '80-Series Tech' started by flintknapper, Dec 26, 2007.

  1. flintknapper

    flintknapper

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    Thanks Rookie,

    Pretty sure I want to bypass the amp (based on what others have said). Some folks have gone with the factory amp., but not many.

    Just looking at the harness...I don't see me using the brown (mute) wire or the blue (antenna) wire. Not sure about any others until I get in there.

    Thanks for the info.
     
  2. SMG1

    SMG1

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    I've got the same issue I think and I can't find where it's been resolved on other post. I am trying to install a new head unit in place of the factory radio because mine quit working in my 96 LX450. I bought the wiring harness that Best Buy suggested for a vehicle with a factory amp. I think I've got it wired correctly but it won't turn on. Does the power go thru the amp first? It's been a while since the factory radio worked but if I remember correctly, it would turn on for a few seconds, then blow the fuse. Now if I plug in the factory radio, it does nothing. Could it be the amp? I'd really appreciate it if you guys could lend some advise!
     
  3. Qball

    Qball

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    Just went through the same thing. Yes delete the stupid amp, it was problematic and sounded bad.

    You just need the standard toyota harness and extend then 16 inches to your head unit and problem solved. Took no more than half an hour and everything works great. If you have a LX then factory sub won't work, but it never added anything anyways.
     
  4. 1973Guppie

    1973Guppie SILVER Star

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    I disconnected the dash speakers and simply plugged in the crutch field harness, sounds great. I don't think it is necessary to not hook up the factory amp


    ...via IH8MUD app
     
  5. David Samuels

    David Samuels

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    I know this is an old, old thread. I've been unable to find any good schematics on this 15 pin setup. Where are the grounds for the four speaker, no amp system? Found the hots, and a diagram that confirms them in the plug. We also have s-gnd and gnd, but no lines that are clearly from the speakers for the negs. Where are they connected? Thanks.
     
  6. Qball

    Qball

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  7. David Samuels

    David Samuels

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    "Yes", it's an old thread? Ha!
     
  8. 1973Guppie

    1973Guppie SILVER Star

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    just buy one of the conversion HU harnesses for your vehicle model and year, it is dead simple, everything is labeled and all you have to do it wire it up to the HU harness, then plug it all in, this conversion harness uses all the factory plugs for power etc.
     
  9. -Spike-

    -Spike-

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    IIRC they use a common ground, probably s-gnd (speaker ground?).
     
  10. Malleus

    Malleus

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    There's a common ground, inside the harness:
    upload_2018-2-13_13-8-21.png

    FWIW, the Metra pigtails supplied by Crutchfield have these covered:

    20171219_093547.jpg

    I removed the leads in the two white connectors, attached new terminals to the ends of the leads from the black head unit connector, and inserted them into the white connectors. This not only reduces the amount of wire volume behind the head unit, but it completely removes the bullet connector splice which is necessary when you use the material as supplied.