Extra wire hanging near interior fuse panel. Any ideas?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by mschoono, Sep 1, 2015.

  1. mschoono

    mschoono Junior Member

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    I got into the car this morning, and disengaged the parking brake with my foot. There was a lot of dew on the windshield, so I flipped the lever on the steering column to turn on the wipers...and nada. I didn't really have time to investigate, so I wiped off the windshield by hand and drove to work. I figured I'd blown a fuse.
    I pulled into the lot, got out of the car, and saw a 30 amp fuse on the floor. This was indeed the wiper fuse, but how on earth did it fall out? I knelt down to replace it, and noticed a black wire hanging down from just to the left of the parking brake pedal. It has a terminal sticking off the end of it that seems to have been deformed (see attached photos). Does anyone know what this wire is for?
    I'm assuming it was somehow wedged in with the wiper fuse, and it got yanked when I disengaged the brake this morning, deforming the end and in turn pulling the fuse out. I could be wrong about that, but in any case I'd like to know where it's supposed to go. Does anyone else have this same wire going to their fuse panel? As you can see in the photos, it goes over the plastic panel to the left of the pedal. It then goes down behind the panel.

    Thanks!
    IMG_20150901_172854630.jpg IMG_20150901_172831863_HDR.jpg
     
    #1 mschoono, Sep 1, 2015
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Did someone install aftermarket electronics on that car? If so, perhaps that wire was taking 12VDC via the fuse that fell out.
     
    #2 Patrick Wong, Sep 1, 2015
  3. ChapmanF

    ChapmanF Senior Member

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    I'll second Patrick's guess. That looks a lot like the old really-not-smart way to add a new circuit in a car: just a plain metal tab you would attach a wire to and jam it down alongside one leg of an existing fuse for some other circuit. Depending on which leg you happen to jam it down, you either have your new circuit also drawing from the old fuse (which isn't a problem as long as the total loads don't blow the fuse), or you have the new circuit totally unprotected (which isn't a problem as long as it doesn't burn your car up).

    A better way to do it is with what's called an "add a circuit" (Mr. Google knows). You pick an existing fuse to take out of your fuse box, putting the add-a-circuit in its place. The add-a-circuit has two fuse slots, one for the original fuse you took out, which still protects the original circuit, and one for the circuit you're adding, which you crimp to the pigtail wire on the add-a-circuit.

    So what I'd recommend is, don't try reattaching that original tap at all. If you don't know or can't find out what that added circuit was for, and you don't miss it, don't reattach it at all ... problem solved. Just put the wiper fuse back so you have wipers.

    If you know what was added and it's something you care about, cut off that funky terminal, pick up a real add-a-circuit, and use that to hook it back up more safely. (You might also want to take a close look at the rest of the workmanship in adding that whatever-it-is, considering what this terminal says about whoever did it.)

    -Chap
     
    #3 ChapmanF, Sep 1, 2015
  4. xliderider

    xliderider Senior Member

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    Here's a picture of an add a circuit fuse tap:

    [​IMG]

    Trace the wire and see where it goes.
     
    #4 xliderider, Sep 1, 2015
  5. mschoono

    mschoono Junior Member

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    Thanks for the tips! We bought the car in mid July, and when we got it home, realized that we had been given an extra key fob (with no buttons or markings) that apparently did nothing. After some investigation, I determined it was a LoJack fob, and that the vehicle had a system installed. After your advice last night, I figured out that the errant wire is the 12V supply for the LoJack system. The terminal had been (rather crudely) installed on the low side of the 30A wiper fuse. Capped it off and that's that. Thanks again for the help!
     
    #5 mschoono, Sep 2, 2015
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