2012 Gen 3. Fuse Panel Diagram Incorrect - Low Beam HL Fuses??

Discussion in 'Gen 3 Prius Audio and Electronics' started by jc60752, Nov 3, 2016.

  1. jc60752

    jc60752 New Member

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    In the image, the green dots on the right show the slots that should contain fuses but do not, as indicated by the diagram on the left.

    Is there a corrected version? Does anyone know where the H-LP-LH LO fuse is???

    2012Gen3PriusFuse.jpg
     
  2. Rebound

    Rebound Senior Member

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    There are different trim levels of Prius. The unused fuse locations could be for models with auto leveling headlights, LED headlights, Hid lights, or the dynamic cruise control, power seats, seat heaters, or any or several other options your car doesn't have.
     
  3. ChapmanF

    ChapmanF Senior Member

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    I had been meaning to mention the same thing, and Rebound beat me to it. Overall, I find the legends printed in the fuse box covers to be pretty much as accurate as the ones in your grandfather's fusebox at home ... whatever is written next to one fuse is probably at least related to one thing that's fed on that circuit, but there can be other things you wouldn't think of, look in the wiring diagram and it's full of surprises, and some of them depend on the trim levels and options.

    If you look at this post here, it's about somebody else's different question, but it shows the way Toyota marks up optional wiring alternatives in the wiring diagram. Look at the way they have numbered notes *1, *2, *3, and so on, and then some wires in the diagram are shown going one place with a *1 or some other place with a *2, so you look in the notes to see which number matches your options, and then you look for the bits matching that in the diagram.

    -Chap
     
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  4. Robert Holt

    Robert Holt Senior Member

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    Can those "spare" fuse openings in that fuse block have a fuse inserted and then be used to power a new circuit? Say, for example, a new fuse to power a new set of LED DRLs installed up front with a fuse-protected power supply?
     
  5. ChapmanF

    ChapmanF Senior Member

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    When you look up that box in the wiring diagram, one of the pages you'll find is "internal connections" which, just as it sounds, shows you how all of those slots are connected internally, which will show you where the open slots get their power from, where the downstream connection comes out, etc.

    -Chap
     
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  6. Robert Holt

    Robert Holt Senior Member

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    Thank you, Chap!
    Although I must say this wiring diagram is at least one order of magnitude more complicated than the 1963 Plymouth Valiant that I rewired long ago!
    Wow, need to pick an extra slot where an extra 2 or 3 amp draw will not overload things. Time for homework.
     
  7. RRxing

    RRxing Senior Member

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    From the 2010 fuse layout:
    Top left dot is for the headlight cleaner (washer).
    Bottom left dot shows "No Circuit."
    The "S-Horn" fuse on the attached shows it as fuse #4 "No Circuit", but in a different location than your photo. Your photo also shows it as a larger fuse. May also be "No Circuit" for you as well.
    The 40A P/I 2 fuse (near bottom center) is for low beams (H-LP-LH LO)

    See attached (for 2010)
     

    Attached Files:

    #7 RRxing, Nov 7, 2016
    Last edited: Nov 7, 2016
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  8. Robert Holt

    Robert Holt Senior Member

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    Thanks for that PDF!
    Am I correct that one simple approach to powering additional LED DRLs,on my Prius would be the following:
    As we do not have heated seats , could I simply tap into the fuse position 4 and 5 of the left side instrument panel fuse box using 5 amp fuses (maximum draw should be 1-2 Amps.)?
    Or could those fuse positions be used for something completely different on a 2012 trim level 3 hatchback?
     
  9. ChapmanF

    ChapmanF Senior Member

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    No doubt! :)

    On the other hand, I bet that Valiant wiring diagram was all on sheets of paper you'd have to follow around with your finger, and dog-ear the corners or stick pencils and wrenches in to hold your place. The interactive way you can just click around the online Toyota diagrams can make life really easy once you get the hang of it. This post (though it's about somebody else's question) should give the idea.

    I would definitely check the diagram for your model year, and pay attention to the *1, *2, ... option markings, to be sure you're making the right conclusions for your car.

    -Chap
     
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  10. Robert Holt

    Robert Holt Senior Member

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    The temptation to simply bull through to a solution without doing my homework is quite strong.
    I will try to resist that temptation as such a course of action can, of course, have disastrous consequences .
    Thank you, Chap!
     
  11. Rebound

    Rebound Senior Member

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    Basically, no. It's much less work to just use an in-line fuse holder for a new circuit than to remove the fuse box housing, install wiring underneath with a fuse holder, and wire it up. It may be that there are unused terminal screws attached to fuseholders, which could make it easier, but I'm not sure.
     
  12. xliderider

    xliderider Senior Member

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    The Gen 3 has two open 1/4 inch terminals at the back of the engine fuse box that is constant +12v power. In this picture, it has two red wires going to them:

    [​IMG]
     
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  13. Robert Holt

    Robert Holt Senior Member

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    Thank you. That could be useful for this install! Need to get slightly smaller light assemblies to fit the tow hook openings as the 2"x2" metal housings are about 1/8" too large unless I start cutting out the slots, which I would prefer to not do.
     
  14. Rebound

    Rebound Senior Member

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    Just to be clear -- those terminals aren't fused, and you should add an inline fuse holder with fuse if you use those power terminals.
     
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  15. xliderider

    xliderider Senior Member

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    Fuse holder, and controlled by a relay. (y)
     
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  16. saak

    saak Junior Member

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    My 2010 Gen3 Prius, rear defroster not working, could you please help me finding the fuse or relay, I dont see any in under the hood fuse box.
     
  17. xliderider

    xliderider Senior Member

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    There's a fuse panel under the driver's side of the dashboard, next to the kick panel as well. The fuse locations are listed on the inside of the cover.
     
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  18. MH1

    MH1 New Member

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    Hello there,

    I have a 2013 Prius Plug-in. HID headlamps installed (before me). One of the sides went out, so I purchased 2 new kits.
    Installed them but both sides didn't work. I then swapped out lamps, ballasts, wires, and then finally ended up installing all the old components but was never able to get the original working lamp back to working.
    I figured it was a fuse issue, opened the fuse box, and the 2 fuses and 1 relay labeled for the low beams are "missing", similar to the picture in the #1 post by jc60752.
    Are the fuses not needed for HID installation?
    I'm trying to troubleshoot what I can on my side before returning the kits back for a replacement.
    Thanks!

    [​IMG]
     
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