Welcome to PriusChat

We'd love to have you join our community and participate in the conversation! Sign up for FREE today.

Sign Up
  1. TGB4 2014 Prius Convention Hotel Discounts are ending this week. Click for more information. All Access registration with personalized items ends Sept 1. Register now!

How to Auto-on Headlight installation

Discussion in 'Prius c Accessories and Modifications' started by Logical, Apr 14, 2012.

Social Buttons

  1. Logical

    Logical Junior Member

    Joined:
    Dec 11, 2003
    Messages:
    82
    Likes Received:
    24
    Location:
    St. Louis, Missouri
    Your Vehicle Year:
    2012 Prius c
    Model:
    Four
    Doing the Prius C is very similar to doing a regular Prius.

    this is from post #10 Automatic Headlights on the Prius 2010 Accessories Modifications that I used for doing my C



    post 3

    here is write up for the preparing the headlight module. I followed it as written for Part I, Part 2 is little different, so I rewrote it. Part 3 is also revised from the original.



    I used velcro pieces instead of foam tape.

    Part 2
    the disassembly is part Two, the Prius C is simpler than the regular Prius.

    Turn the steering wheel all the way to the left, remove the screw that is visible,
    Turn the steering wheel all the way to the right, remove the screw that is visible.
    The third screw is located underneath in the middle.
    Once the screws are out, pry the top and bottom apart. I purchased a set of dash disassembly tools from harbor freight for $5, so that I did not mess things up. Once the bottom is off the connections points are now accessible.
    Next I pried the dash panel off in the lower left corner above the ODB Connector, this is where installed the module.

    End of part 2

    Part 3 is installation, I made minor revised hawkmoon77’s installation steps

    I connected the power(red) and yellow together and connected them to the grey wire of the power outlet.

    I connected the black wire and one of the relay lines to a black/white cable I found behind the dash panel area that I removed.

    I connected the other relay line to pin 19 of
    http://priuschat.com/forums/attachments/gen-iii-2010-prius-accessories-modifications/16813d1248099406-automatic-headlights-l47.jpg

    the Violet wire (12v+Wipers) is connected to the large white wire in the harness under the wiper switch.

    http://priuschat.com/forums/attachments/gen-iii-2010-prius-accessories-modifications/16814d1248099406-automatic-headlights-l48.jpg



    I installed the sensor on the dash next to one that is already there. I used I piece of #12 solid wire to fish the sensor cable down to module, i push the solid wire down from above. then attached the sensor wire and pulled the sensor wires down to the module. Cleaned up the windshield, ton of fingerprints.

    Tested by turning the car on. the lights came on!, pointed the trouble light at the sensor and they turned off. next I turned the wipers on and the came back on.

    now you plug cable into the module, that I used velcro to stitch it to the back of the dash panel piece. the relay I velcroed to behind the dash up to left of the panel I removed.

    Tested by turning the car on. the lights came on!, pointed the trouble light at the sensor and they turned off. next I turned the wipers on and the came back on.


    Everything should now installed

    now put the covers back on complete the installation.

    Thoughts:
    The pins in two connectors under the steering wheel are very very fragile, I suggest making the attachment to them without disconnecting them. I broke a pin in the headlight one by not being careful about unplugging and replugging the connector. Had to replace it, big pain.

    installation time should be about 45 minutes if I had to do it again.


    a very Special Thanks to hawkmoon77 for doing the orginal Prius 2010 auto headlight write up.

    i include some picture of the underside of steering wheel for reference.

    Attached Files:

    2 people like this.
  2. ProximalSuns

    ProximalSuns Senior Member

    Joined:
    Mar 24, 2012
    Messages:
    1,882
    Likes Received:
    16
    Location:
    PNW
    Your Vehicle Year:
    2012 Prius
    Model:
    Three


    You da Man!

    I'm printing out your posting and taking it to my local Toyota dealer and cajoling them into doing it.
  3. SquallLHeart

    SquallLHeart The Techie Guy

    Joined:
    Mar 10, 2012
    Messages:
    815
    Likes Received:
    220
    Location:
    San Jose, CA
    Your Vehicle Year:
    2012 Prius c
    Model:
    Two


    umm.. most Toyota dealerships would refuse to install something that isn't made by Toyota or an affiliate of (i.e. TRD)

    they don't want.. nor would they want to deal with a product that they could not really provide warranty and would not want to be liable for something if it went wrong.

    these types of installs are left to the enthusiasts.. and/or some other shop that'll probably charge you a lot for for something that you could do yourself... or perhaps a friend.
  4. meehow09

    meehow09 New Member

    Joined:
    Feb 22, 2012
    Messages:
    42
    Likes Received:
    9
    Location:
    Chicago
    Your Vehicle Year:
    2012 Prius c
    Model:
    Three
    After this install, is the light switch left in the ON or OFF position so that it can turn itself on and off automatically?





  5. Logical

    Logical Junior Member

    Joined:
    Dec 11, 2003
    Messages:
    82
    Likes Received:
    24
    Location:
    St. Louis, Missouri
    Your Vehicle Year:
    2012 Prius c
    Model:
    Four
    off, or in DRL position if you want them on when the headlights are not on.
  6. meehow09

    meehow09 New Member

    Joined:
    Feb 22, 2012
    Messages:
    42
    Likes Received:
    9
    Location:
    Chicago
    Your Vehicle Year:
    2012 Prius c
    Model:
    Three
    I received the auto headlight kit but I do not understand 2a of part 1 about the relays. Both relays are connected to each other by a red wire. One relay has a red, brown, 2 blue wires the other has 2 green, a purple and 2 red wires. What exactly do I do to separate the relays? I'm sorry, but you just said to remove the relay with the red and green wires but I don't know how or what to do with the other wires.
  7. Logical

    Logical Junior Member

    Joined:
    Dec 11, 2003
    Messages:
    82
    Likes Received:
    24
    Location:
    St. Louis, Missouri
    Your Vehicle Year:
    2012 Prius c
    Model:
    Four
    Automatic Headlights | PriusChat
    is the original post i based the Prius C on, Your colors, don't seem to match with what I had. The common one, (red) i cut off near the relay base of the relay that got removed. If I were you , I would match up wires with the function listed in the write up. In mine there was a small piece of paper with a description of what each wire was far. Sounds like they have changed colors....
  8. meehow09

    meehow09 New Member

    Joined:
    Feb 22, 2012
    Messages:
    42
    Likes Received:
    9
    Location:
    Chicago
    Your Vehicle Year:
    2012 Prius c
    Model:
    Three
    I attached some pictures to this reply of the 2 relays connected with wires. Can you please help me to tell me what do do with each wire and relay?



    Attached Files:

  9. Logical

    Logical Junior Member

    Joined:
    Dec 11, 2003
    Messages:
    82
    Likes Received:
    24
    Location:
    St. Louis, Missouri
    Your Vehicle Year:
    2012 Prius c
    Model:
    Four


    cut the red wire at the point where it comes out relay with the two red on it.i used the bottom relay....

    the purple and big green go the connector to turn the headlights on

    the red and small green goes to the controller, there should be more wires come connected to controller, (not pictured). some of those get cut off, see the instructions.


    logical
  10. meehow09

    meehow09 New Member

    Joined:
    Feb 22, 2012
    Messages:
    42
    Likes Received:
    9
    Location:
    Chicago
    Your Vehicle Year:
    2012 Prius c
    Model:
    Three
    Sorry, but which red do I cut? The red that connects to both relays or both red wires?

    And I keep the relay with the green and purple wires?



  11. Logical

    Logical Junior Member

    Joined:
    Dec 11, 2003
    Messages:
    82
    Likes Received:
    24
    Location:
    St. Louis, Missouri
    Your Vehicle Year:
    2012 Prius c
    Model:
    Four
    red one that connected to both relays.

    green and purple....yes
  12. meehow09

    meehow09 New Member

    Joined:
    Feb 22, 2012
    Messages:
    42
    Likes Received:
    9
    Location:
    Chicago
    Your Vehicle Year:
    2012 Prius c
    Model:
    Three
    I tried installing the module today but I got stuck. I left off at connecting the red and yellow wires from the main harness of the module but I do not know where or how to get to the gray wire of the power outlet is to connect the red and yellow wires to?
  13. Logical

    Logical Junior Member

    Joined:
    Dec 11, 2003
    Messages:
    82
    Likes Received:
    24
    Location:
    St. Louis, Missouri
    Your Vehicle Year:
    2012 Prius c
    Model:
    Four


    the grey wire is on the passenger side of the dash, start at back of the power outlet on the dash and look at the back of the outlet and follow it until you can find a place to make the a connection fish it across to where you are mounting the module.
  14. meehow09

    meehow09 New Member

    Joined:
    Feb 22, 2012
    Messages:
    42
    Likes Received:
    9
    Location:
    Chicago
    Your Vehicle Year:
    2012 Prius c
    Model:
    Three
    I tried prying the panel with the outlet off, but I do not even know where to start because I'm scared it will crack.
  15. Logical

    Logical Junior Member

    Joined:
    Dec 11, 2003
    Messages:
    82
    Likes Received:
    24
    Location:
    St. Louis, Missouri
    Your Vehicle Year:
    2012 Prius c
    Model:
    Four
    you can access it by removing the glove box. i did not remove the panel, got at thru the glove box. the glove box come off really.....
  16. ROLOPR

    ROLOPR Member

    Joined:
    May 22, 2012
    Messages:
    428
    Likes Received:
    68
    Location:
    Puerto Rico
    Your Vehicle Year:
    2012 Prius c
    Model:
    Two
  17. eco31

    eco31 Member

    Joined:
    Jul 12, 2012
    Messages:
    193
    Likes Received:
    48
    Location:
    IE
    Your Vehicle Year:
    2012 Prius c
    Model:
    Four


    Awesome post! I have to admit this is one of the most useful post! Thanks for doing the homework and sharing with us!
  18. WD0AFQ

    WD0AFQ Active Member

    Joined:
    Jul 6, 2012
    Messages:
    619
    Likes Received:
    148
    Location:
    Dexter, Mo.
    Your Vehicle Year:
    2012 Prius c
    Model:
    Two
    Yes, this is great post and I'd like to do it to my C. Found the kit for 30 bux shipped. Hope I can figure it out using the posts in this thread.
    Thanks,
    Dan
  19. WD0AFQ

    WD0AFQ Active Member

    Joined:
    Jul 6, 2012
    Messages:
    619
    Likes Received:
    148
    Location:
    Dexter, Mo.
    Your Vehicle Year:
    2012 Prius c
    Model:
    Two
    Got mine ordered. I have read the instructions a few times that are posted in this thread. I am sure they will make more sense once I get the module. I may very well be back here looking for help next week.
    Thanks for making me aware that this thing existed.
    Dan
  20. WD0AFQ

    WD0AFQ Active Member

    Joined:
    Jul 6, 2012
    Messages:
    619
    Likes Received:
    148
    Location:
    Dexter, Mo.
    Your Vehicle Year:
    2012 Prius c
    Model:
    Two
    Got my kit a couple of days ago. Can't wait to get it installed. I miss those automatic headlights on this vehicle. Hoping I can follow the instructions provided above.
    Thanks again for posting this for us C owners.
    Dan
Similar Threads: Auto-on Headlight
Forum Title Date
Gen III 2010+ Prius Accessories and Modifications Replacing 2014 Prius turn signal lever for Auto-On Headlights Aug 4, 2014
Prius v Accessories and Modifications Auto-on headlights for v2 and v3 Dec 2, 2012
Gen III 2010+ Prius Accessories and Modifications Auto-on Headlight Nov 10, 2011
Gen III 2010+ Prius Main Forum No Auto-on Headlights in US: Mystery Solved Mar 28, 2011
Gen III 2010+ Prius Main Forum Why no auto-on headlights May 30, 2009