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What is the easiest firewall pass through to get a wire from the engine compartment to interior

Discussion in 'Gen 3 Prius Main Forum' started by Johnny Cakes, Jul 21, 2021.

  1. Johnny Cakes

    Johnny Cakes Senior Member

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    Searched on "FIREWALL" and didn't find an answer to this question. Need to pass a wire through from engine compartment to passenger's compartment. Preferably easy and pre-existing hole. Any ideas?
     
  2. ChapmanF

    ChapmanF Senior Member

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    Each of the two rubber grommets shown where the engine compartment wire harness passes through the firewall (one near the right end of the firewall, and one just inboard of the brake actuator) includes at least one (maybe two?) extra rubber nipples that can be pierced to pass additional wires through.

    groms.png
     
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  3. Mendel Leisk

    Mendel Leisk Senior Member

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    D99E4CA4-FB6C-4505-87D5-B0B75023DAEA.jpeg

    These two? And that’s a plan view, front end towards bottom of pic? Probably seeing the actual item is easier; the pic just gets you started, but just trying to understand the pic.
     
  4. Georgina Rudkus

    Georgina Rudkus Senior Member

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    Drill a new hole. Use a hollow punch cutter to cut through the carpet and the insulation, before drilling with a step Unibit. Then, use a runner grommet to protect the wires.

    A technician servicing the car will immediately know that it is not OEM and to segregate it from the original systems to make his or her job easier.
     
    #4 Georgina Rudkus, Jul 22, 2021
    Last edited: Jul 22, 2021
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  5. ChapmanF

    ChapmanF Senior Member

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    Yes.

    The dog-leg taken by the wire harness near the one grommet is where it goes under the brake actuator assembly, which may help with locating that grommet in the engine compartment. From within the cabin, it would therefore be somewhat to the right of the brake pedal pivot, closer to above the go pedal. That's the one I poked my fog light wire through.

    As the grommets are already designed for this kind of extensibility, I wouldn't see much need to drill extra holes.

    What's the new wire needed for?
     
    #5 ChapmanF, Jul 22, 2021
    Last edited: Jul 22, 2021
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  6. Grit

    Grit Senior Member

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    one feller found a way to snake a cable from the side of engine wall, next to the driver side wiper end of the chassis, up between the driver door fender and into the left instrumental panel perfectly. I thought that was genius so no drilling required.
     
    #6 Grit, Jul 22, 2021
    Last edited: Jul 22, 2021
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  7. xliderider

    xliderider Senior Member

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    The grommet location and how to poke through it is described in the installation instructions in the first post of this thread.

    https://priuschat.com/index.php?threads/80168/

    I used a coat hanger with the wires taped onto it to pass the wires for my foglight switch, after poking through a nipple on the grommet by the brake actuator with an icepick first.

    Posted via the PriusChat mobile app.
     
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  8. Johnny Cakes

    Johnny Cakes Senior Member

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    Thanks all (well, mostly all :) ) Exactly what I needed to know.

    Front camera
     
  9. doctorman

    doctorman Member

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    does any one have the picture of the passenger side access?
     
  10. Mendel Leisk

    Mendel Leisk Senior Member

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    Thought keeps coming to mind: wouldn’t it be nice if auto manufacturers would pre-wire for a rear camera.

    A purpose-built cell phone holder clip point on the dash would be nice too.
     
  11. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    They are all prewired for cameras now, and they even include the camera, because it has been required by regulation for about six years now.

    As far as a phone holder? They would rather you create your own liabilities to enable distracted driving, and it undercuts the automakers' attempts to sell you an upgraded irritainment & navigation system.
     
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  12. black_jmyntrn

    black_jmyntrn Senior Member

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    why go through firewall? think outside the box... using a Mini Cable Snake go through the fender...