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Practical test for Hot Fuses

Discussion in 'Prius c Technical Discussion' started by Bigboi, Sep 28, 2016.

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  1. Bigboi

    Bigboi Member

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    Hey PriusBros I just got 2 seat warmers and rather than drain the 12v accessory since it is being used to charge 2 phones, a dash cam, and LED lights, I've decided to tap into the fuse box on the driver side.

    My question is: which fuses are hot I.e. power locks?

    Is it possible for me to see right away if I just plug in an add a fuse and see if my seat warmers are powered while the car is off?

    Also, what fuse type does the 2015 Prius C take? Standard? Mini? I'm eyeballing it but can't tell.

    Last question: since I don't have or plan on having fog lights or sunroof, can I tap those to power my 2 seat warmers? Are those fuses hot?

    I don't want to accidently drain my battery because these seat warmers don't have auto off due to accidently tapping into a hot always on fuse. Thank you!
     
  2. ChapmanF

    ChapmanF Senior Member

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    Say, in a c, isn't the aux battery itself right under the back seat or something? (I don't have a c, but I thought I remembered that.)

    That could be a pretty convenient place to tap for warmers in the two front seats, and you wouldn't have to decipher the front fuse/junction box. (That's kind of like most people's fuse boxes at home ... there's a cryptic label for each fuse, but usually only enough to give you a broad hint about one of the circuits that fuse feeds, and nothing about the other three or four that probably also branch off of it. I go straight to the wiring diagram whenever I need to really know what's on what fuse....)

    I ended up adding several fuses and a low-voltage disconnect right at the battery, in both my old Gen 1 and my current Gen 3. The low-voltage disconnect module solves the "I don't want to discharge my battery" problem and without even having to hunt down a circuit that's only powered when the car is on: the module can simply tell because it recognizes the voltage increase when the car goes to READY.

    In my first Gen 1 version, I kind of homebrewed the low-voltage disconnect, but later I just bought the one from InPower that I mention in the later post, which does pretty much everything I wanted.

    -Chap
     
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  3. Bigboi

    Bigboi Member

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    Now that is a great idea, I was worried since the aux battery is always on it might drain its juice if the seat warmers are accidently left on. Any particularly names of items I should get to wire it to my 12v seat warmers? I'm thinking any generic low voltage cutoff thing should work as long as it has a socket connection I can connect to without having to splice my wires woop woop!
     
  4. exstudent

    exstudent Senior Member

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    The 12V will self discharge by itself.

    Leaving the seats on accidently, say overnight, ABSOLUTELY will discharge the 12V battery. And likely to the point of requiring a jump start. B/C of this likely scenario, you may want to wire into a circuit that is IG-ON powered, or make a new circuit that will do this.

    You seem to be getting in over your head with this project. Might be safer for you to have a car stereo shop do the wiring for you.
     
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  5. Bigboi

    Bigboi Member

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    I don't want to hurt my baby!
     
  6. exstudent

    exstudent Senior Member

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    Are the "cigarrete lighter" ports, now called 12V auxiliary port, wired to ACC or IG-ON, in your C? If so, the seat warmer could use this, assuming the amp draw is not too high. If the seat warmer does not have a cigarete end, one can be attached to it easily.
     
  7. ChapmanF

    ChapmanF Senior Member

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    My earlier post contained links to other posts with details about how I did it both in Gen 1 and Gen 3, which should give you a lot of ideas, including the off-the-shelf low voltage disconnect I used later, which has some nice features.

    -Chap
     
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  8. Mendel Leisk

    Mendel Leisk Senior Member

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    Invest in a multi meter; test your potential connection point.
     
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