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2012 Prius horn problem

Discussion in 'Gen 3 Prius Technical Discussion' started by Scott_R, Jan 3, 2019.

  1. Scott_R

    Scott_R Member

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    Thanks for the pictures. The bolts in the hood hook... nothing on the other side (nuts)?

    I think I'm just going to go with the gel-caps. I have them already anyway; worst case scenario if it fails is that I have to reconnect.
     
  2. ChapmanF

    ChapmanF Senior Member

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    The corrugated stuff is called split-loom (for whatever reason), and usually has a lengthwise slit. Once you unwrap the tape around the end, you can probably slide the wires right out through the slit. Keep your splice tidy enough and you might also be able to tuck them right back in.

    What are you going to gel-cap-twist to what? Have you obtained a repair terminal?
     
  3. Scott_R

    Scott_R Member

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    Yep, post #11. As far as I can tell it's the right part (seems to match what I removed) and it has a pigtail. So assuming there are no problems stripping the wire (i.e., I can fit the stripper in there and the wire isn't corroded much more) I can just twist the two ends together. $8.99 plus shipping on eBay. Would you believe that this site had it for $75???? For that much it ought to include installation!

    Thanks for the info about the split-loom.
     
  4. ChapmanF

    ChapmanF Senior Member

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    Ah, I guess that would do it. (If you bought the repair terminal from Toyota, it would just be the terminal itself on a pigtail of wire, and you would click it into your existing plastic connector housing after extracting the broken old terminal. But $11.99 including shipping is no more than the Toyota item, and including the housing too, not bad.

    If you can fit your wire strippers in there, you can probably fit a crimp tool too, and do a Toyota-quality repair. (As for access, even taking the bumper cover right off really isn't that bad ... one of those jobs that's easy to put off for thinking it'll take longer than it really does once you set about it.)
     
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  5. bisco

    bisco cookie crumbler

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    if the toyota quality only lasted 6 years, maybe use the sprinkler nut
     
  6. Mendel Leisk

    Mendel Leisk Senior Member

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    There's rarely if ever a loose nut on the back side. Typically (and in this case), there's a "weld-nut", a square nut welded on the far side of the hole in the sheet metal. It acts like a threaded hole.
     
  7. ChapmanF

    ChapmanF Senior Member

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    Not sure I can judge the splice quality of something that wasn't spliced.
     
  8. bisco

    bisco cookie crumbler

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    agreed. but you can judge the quality of the original connection, which must have been a factory defect imo. pretty unusual failure
     
  9. ChapmanF

    ChapmanF Senior Member

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    It looks like that connector's a non-waterproof design, like the ones common back in the '70s, where yes, the wires sometimes used to corrode through and fall out the end of the connector. Weird choice in a modern car, but I guess horns themselves still get built with that exposed flat quick-connect, so using a fancier weatherproof connector to plug onto it would maybe just seem like overkill.

    Anyway, the replacement connector is probably going to be of the same construction and the same disadvantages (perhaps I would smush a blob of sealant into the back of it before I was done).

    But there will also be a splice involved that wasn't there before. Toyota's standards for those are pretty stringent ...either covered with sealant-exuding heat-shrink, or wrapped very thoroughly in self-fusing rescue tape.
     
  10. Scott_R

    Scott_R Member

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    I picked up a box of various-sized adhesive-lined watertight heat-shrink butt connectors. With any luck I can get the heat gun in there.
     
  11. Scott_R

    Scott_R Member

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    The part came today (two days after USPS said it would, but there you go).
    Taking apart the trim etc was easy enough. I took off the trim over radiator, then the latch for the hood, then the emblem.

    Stripping the remaining wire was, as I'd suspected, one of the trickier parts. It's a really thin gauge, thinner than I'd have thought. The insulation around it is... odd. You can sort of see it back in post #4, like there's more in there than just the wire. I'm still not sure about it. I stripping off less than I'd have liked, but I didn't have much room to work with--turns out that outer conduit isn't split, so if I wanted more room I'd have to have taken more of *that* off too, and I wasn't sure how to strip just that off without effecting the inner wire, especially with the limited maneuvering room.

    And that brought me to an unexpected problem: the gauge for the pigtail on the new connector was considerably larger than the wire in the harness... though maybe I didn't get a good sample of the latter--meaning, it's possible that the end I had wasn't really so narrow, just that it was what good wire was left when the corroded stuff came off. But it means that I had to compromise with the butt connector, using one that would fit the pigtail but was maybe a bit larger than optimal for the harness wire.

    Before crimping I tested the horn and both worked. So I crimped it in place and took out the heat gun. Strangely, one end shrank easily enough but the other needed a lot of focus of the gun before it finally gave in and shrank. I then dabbed some low-temp application silicone over it (making a right mess in the process). I'm crossing my fingers that the butt connector will hold.

    Thanks for your input, everyone. One more thing, though: while working under there, I saw this; should there be a boot over those wires towards the right of center?

    underhood.JPG
     
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  12. Mendel Leisk

    Mendel Leisk Senior Member

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    upload_2019-1-9_11-55-22.png

    ^ Man that's Corrosion with a capital C.


    upload_2019-1-9_11-52-4.png

    That's normal for North American Prius. I think in other parts of the world there are covers, and some members here have purchased them. Someone might know the part number or contact info.

    There's other items similar. For example, on the engine underpanel, there's some rather large openings, by design. There is a cover that can be purchased (from Japan?).
     
    #32 Mendel Leisk, Jan 9, 2019
    Last edited: Jan 9, 2019
  13. Scott_R

    Scott_R Member

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    I live near the ocean (or, at least, a saltwater bay connected to it). As in, it's connected to my back yard. As in, the storm surge would have been above my head during Hurricane Sandy. So I guess six and a half years of salty air has taken a toll.

    Whew. Good to know. When I last checked on the horn issue, I also noticed that the engine air filter cover hadn't been fully fastened down--part of the air filter was sticking out. Presumably that happened when I last took the car in for service (at a dealer), but then I saw this latest thing.... there's that connector right above the bare wires that has a cover, and it was similar enough that I figured there was something missing.

    This past September someone doored me (opening their door just as I drove by) and took off my sideview mirror and dented and scraped both passenger side doors (they tried blaming me, saying I was speeding, but I told them NOT to try that: I had the whole thing on dash cam, which I showed to the cops and the insurance co). I know they have to detach some of the hybrid components, such as the battery, when they repaint (since they bake it on), so I thought maybe a part had gotten misplaced.
     
  14. Mendel Leisk

    Mendel Leisk Senior Member

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    Our car's had partial repaint several times now. Maybe depends on the shop, but I don't think they've ever needed to disconnect anything, or used a bake oven. They use water based. Perhaps the need for bake has gone away?

    I recall a recent video someone here linked, and I believe it was somewhere in Vancouver, a mobile bodyshop guy, doing everything in somebody's driveway. It was a Matrix with stoved-in rear quarter panel. He did all the bodyshop tricks right there, finished off with many paint coats. Interesting watch:

     
  15. ASRDogman

    ASRDogman Senior Member

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    Rust, never sleeps!!!!! :)
     
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  16. Grit

    Grit Senior Member

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    Toyota didn't put one on that particular exposed connection. Their profit margin would take a hit if they had to put a $12 part that would prolong the life of the electrical component on every single reliable turd gen prius. I purchased the actual boot but was scared shitless to put clamp it on because how brittle the latch was, @RMB was there to help me.
     
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  17. Scott_R

    Scott_R Member

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    I've been dealing with this autobody shop since the about the mid- 2000's. Everything they've done has held--the repaint has been at least as good as OEM, so I can't really argue with their methods. And they go around and fix up other minor chips and scratches, too, more than would just be needed for feathering.
     
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  18. ChapmanF

    ChapmanF Senior Member

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    When using butt splices, I've sometimes been known, if its bigger enough, to strip the skinny wire twice as far, and bend it double, to be meatier inside the crimp.

    Toyota's specified crimp sleeves, as it happens, are parallel splices, not butt splices; they are sized for the new and old wire lying overlapped, not end to end, which kind of ameliorates that problem.
     
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