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Partially failed Clockspring workaround

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by 40mpgnot40mph, Dec 8, 2019.

  1. 40mpgnot40mph

    40mpgnot40mph Junior Member

    Joined:
    Dec 10, 2018
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    Location:
    California
    Vehicle:
    2010 Prius
    Model:
    Two
    So I have a 2010 Prius, and ever since I got it in November 2018, the horn has never worked. The strangest part was that everything else worked. Cruise control, the remote radio and A/C controls all worked and the airbag light never light up. I finally decided to fix that horn, and a quick search for new oem clocksprings had me looking for alternative sources of the issue. I worked backwards from the Horns, integration relay all the way to the clockspring, which was completely identified as the source of the broken connection. I used the pdfs (That i found on another forum post here at Prius Chat and are on this post) just to double check everything else but the clockspring was working right.

    The rest of the thread is going to assume that you already watched the videos on how to disassemble to steering wheel to the point where you can access the blue wire that goes the airbag pad. It also assumes that you removed the bottom half of the steering column cover to the point you can access the other connectors to the clock spring.

    Once both connections on each side of the clock spring is exposed, you need to test for signal continuity (Can pass a small current or with multimeter with a continuity test function) between an unused pair on pins on each side of the clock spring. Surprisingly, the spacing and size of the connectors of the clock spring are the right size to fit a standard servo lead from R/C world (R/C meaning things like DIY drones, R/C planes, boats and cars). 20191208_121710.jpg
    The picture above shows the connector exposed on the steering wheel side. It did not occur to me to document what I did until I was more than halfway through.

    Once you identify a pair of pins, double check that they are not in use by anything else (already has a wire on the corresponding female connector). In my case, I only needed to move one wire so I only bothered to find one pair of unused pins as shown below. ModPic of Steering Column Connector.jpg ModifiedPic of steering wheel connector.jpg
     

    Attached Files:

    #1 40mpgnot40mph, Dec 8, 2019
    Last edited by a moderator: Dec 9, 2019
  2. 40mpgnot40mph

    40mpgnot40mph Junior Member

    Joined:
    Dec 10, 2018
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    Location:
    California
    Vehicle:
    2010 Prius
    Model:
    Two
    The issue at hand now is how to move the pin on each female connector to their new positions. I found a manual supposedly from toyota, that outlines how to outright replace a connection pair. The relevant information starts on page B-21 per its index, (Page 39 on Chromes page counter). The connector is type L (0.64 spacing) for the steering column side, and the same info was used for the connector on the steering wheel side. You will need a very thin screwdriver or a plain sewing needle. The following instructions is good for both sides, but only the steering column side has pictures. ModPic of Steering Column Connector2.jpg
    First and foremost, you need to open the connector lock, as shown in the picture. It needs to lifted from the surface of the connector and should make a click once lifted. The manual states that it should be lifted up at the points shown on the picture ( connector has little water drop markings to show where), but it can also lifted up from the connector sides. AT NO POINT DOES IT COME OFF. I tried, it just doesn't and the connector is worse for wear from my attempts. For the steering wheel side, the first lock is a bit harder to find, but it will have the same water drop markings. Now for the secondary lock, a needle is the best tool for this. ModPic of Steering Column Connector 2.1.jpg
    That tab is very little and does not take any force to move. If done right, the wire should not take any force to pull out. If you know for sure that you are moving the little tab and wire does not want to come out, let go and close and open the first connector lock. For the steering wheel side, that little hole looks different and has ultra thin plastic (Don't have a picture of it), but same procedure to pull out the wire.

    To insert the pin in its new position, the first connector lock must still be open without a doubt. You may need open the secondary lock as well ( I had to on the steering column side). Once the pin is in its new position, close the first lock and give the wire a light tug. It should not move any more than the wires you did not move. If it does or pulls out completely, repeat previous until it does not come out anymore.
    Once both sides of the clock spring are done, reassemble everything like normal. Once the car is on, double check that steering wheel controls work. For my case, I now have a functional horn without having to replace the clock spring.
     

    Attached Files:

  3. Wooward

    Wooward Junior Member

    Joined:
    Feb 21, 2021
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    Location:
    California
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    I did this exact fix today. I had the same broken pin in my clockspring and I moved it to the same new location as you. Thanks so much for the detailed instructions here. I now have a horn again.


    iPhone ?
     
  4. ChapmanF

    ChapmanF Senior Member

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    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    A resourceful fix, if replacing the spiral cable isn't an option right away.

    Given that all of the conductors in the spiral cable have experienced the exact same amount of flex and wear at any point in the car's life, I would wonder just how long such a repair can be counted on. You've got a bit of randomness taking your side in the matter, but the statistical big picture isn't promising.
     
  5. Troy DIY

    Troy DIY New Member

    Joined:
    Sep 12, 2023
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    Location:
    Fort Lauderdale FL
    Vehicle:
    2007 Prius
    Model:
    II
    Thank you for the post and photos. I’m adding a secondary horn button and the solution you devised will solve my problem. I’m confident that I can add another button to the steering wheel controls for the second horn.