1. Attachments are working again! Check out this thread for more details and to report any other bugs.

2012 GEN 3 Install Fog light Switch to keep DRL to Stay ON

Discussion in 'Gen 3 Prius Accessories and Modifications' started by Paul Hoang, Jun 25, 2015.

  1. Paul Hoang

    Paul Hoang New Member

    Joined:
    Apr 22, 2015
    5
    0
    0
    Location:
    San Jose
    Vehicle:
    2012 Prius
    Model:
    Two
    Hello,

    I have a 2012 Prius and I like the DRL to stay on even when the Headlight are on or off. Currently if Headlights are turn on the DRL turns off and I would like the control to turn DRL on or off.

    I have seen that there's a way to add a Jumper to the fuse box to keep the DRL on at ALL time when the car is started and it's fairly easy. I wanted to know if someone has successful added a Fog light switch to turn on the DRL on even with the Headlights on or off? If yes can you please share step by step instructions with image.

    Thank you in advance
     
  2. xliderider

    xliderider Senior Member

    Joined:
    Apr 19, 2012
    7,842
    3,099
    0
    Location:
    Honolulu, HI
    Vehicle:
    2011 Prius
    Model:
    Three
    It's pretty easy but you're going to have to run wires through the firewall between the engine and passenger compartments. Look at the installation instructions for the oem foglights here in post #1, specifically the part about running a wire through the rubber grommet by the brake pedal.

    2010 Prius OEM-quality Fog Light Kit Now Available! | PriusChat

    If you think you can do this then we can proceed. If you don't feel comfortable doing that, then you will have to settle for the jumpered relay with the always on option.
     
  3. Paul Hoang

    Paul Hoang New Member

    Joined:
    Apr 22, 2015
    5
    0
    0
    Location:
    San Jose
    Vehicle:
    2012 Prius
    Model:
    Two
    Hello,

    I feel comfortable I can run the wires through the firewall and connect to ECU and Fusebox. Lets proceed, Since I am using my LED DRL i am guess I ONLY need to purchase the Fog Light switch correct? What else would I need to Purchase?
     
  4. xliderider

    xliderider Senior Member

    Joined:
    Apr 19, 2012
    7,842
    3,099
    0
    Location:
    Honolulu, HI
    Vehicle:
    2011 Prius
    Model:
    Three
    1) You would need the DRL switch.

    Brand New LED DRL Daytime Running Light Special Switch Control for Toyota Lexus | eBay

    2) Two fuse taps. One to get +12v when in Ready Mode from your passenger compartment fuse box, and the other to tap the fuse in the engine fuse box to supply power to the DRL relay terminal.

    2 Add A Circuit Standard ATM APS Low Profile Blade Style Fuse Holder Tap 5 Amp | eBay

    3) At least 16 feet of 18 awg stranded copper wire.
    4) 2 ft of 14 awg wire.
    5) Assorted crimp connectors and electrical tape.
    6) Extra 10 amp low profile mini ATM fuses (2).
    7) A relay to control the power to the DRLs and to take the load off the DRL switch. Something like this:

    12V Volt 5 Pin 30 40A Amp Automotive SPDT Relay Interlocking Socket Wire Harness | eBay

    8) Optional: Split wire loom, makes the wires more tidy, especially in the engine compartment.

    10 ft 1 4" inch Black Split Loom Wire Hose Cover Conduit Poly Tube Tubing | eBay


    Measure out about 16 feet of the 18 gauge wire, fold the wire in half at the midpoint. Follow the instructions in the oem foglight install guide to push the 18 gauge wire through the firewall rubber grommet (two wires because they're folded over). Pull the wires through the grommet so that one end is near the passenger compartment fuse box near the driver's side footwell, the other end of the wires needs to be by the engine fuse box. At this point, you can cut the wire end where it was folded over on itself to separate it into two wires.

    Refer to the DRL always on mod instructions where the jumper is placed between the fuse and the DRL relay in the engine fuse box. You are going to install one fuse tap device into the appropriate fuse location in the engine compartment fuse box and connect the wire coming out of the low profile mini ATM fuse tap to a 14 gauge wire, connect this to one of the wires on the normally open circuit of your relay (terminal 30 on relay). The other wire on the normally open circuit of the relay (terminal 87) will be connected to the wire that is plugged into the terminal exposed when the DRL relay was removed from the fuse box, use 14 gauge wire for this as well. The ends of the 18 gauge wire will be connected to the coil wires of the relay, terminal 85 and 86 separately. It doesn't matter which wire is connected to which wire. The wire going to terminal 87a on the relay will be unused, make sure it is insulated against short circuits.

    In the passenger compartment, install a fuse tap device into an appropriate fuse location that supplies +12v when in Ready Mode (I use a Seat Heater fuse location (red 10 amp fuse) for +12v when in Ready Mode for my mods.

    Install the DRL switch into the dashboard (refer to the oem foglight installation instructions). Now, you have to locate which wire on the DRL switch is used for the illumination light on the switch. Connect this wire, along with one of the 18 gauge wires pulled through the firewall, and one of the wires on the DRL switched circuit, to the wire from the fuse tap device. Connect the end of the second 18 gauge wire to the second free wire from the DRL switch that controls the switched circuit. There should now be only one free wire from the DRL switch, the black ground wire. Connect the ground wire to a ring terminal and put it under a bolt or screw that is attached to a metal subdash frame. Put everything back together.

    If everything is connected properly, the letters "DRL" on the switch will illuminate when the car is in Ready Mode. The green indicator light on the switch will illuminate when the switch is pressed in (On), and turn off when the switch is disengaged (Off). Additionally, you should have control over your DRL lights. ;)
     
    #4 xliderider, Jun 29, 2015
    Last edited: Jun 29, 2015
    Bohemian Grove likes this.
  5. Paul Hoang

    Paul Hoang New Member

    Joined:
    Apr 22, 2015
    5
    0
    0
    Location:
    San Jose
    Vehicle:
    2012 Prius
    Model:
    Two
    Thanks for the information.... Below is a check list of things I have to buy correct?
    DRL switch
    Two fuse taps
    Two 10v Fuses (To use for the Fuse taps)
    16 ft of 18 Gauge wire
    2 ft of 14 Gauge wire
    One Relay, 12v VOLT 5 Pin 30/40a AMP
     
  6. xliderider

    xliderider Senior Member

    Joined:
    Apr 19, 2012
    7,842
    3,099
    0
    Location:
    Honolulu, HI
    Vehicle:
    2011 Prius
    Model:
    Three
    Yes, and make sure the relay is rated for DC use.
     
  7. ncases

    ncases Senior Member

    Joined:
    Jun 18, 2014
    609
    672
    0
    Location:
    Chicago
    Vehicle:
    2012 Prius
    Model:
    Two
    Love to do this. Update us with pictures thanks.
     
  8. Nobody123

    Nobody123 Member

    Joined:
    Apr 14, 2015
    160
    33
    0
    Location:
    United States
    Vehicle:
    2015 Prius Plug-in
    Model:
    Plug-in Base
    Would you mind pointing me to this info? The search feature on this site is convoluted at best.

    Thank you.
     
  9. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,474
    38,106
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    ^ I agree. You can type the precise thread title and it STILL won't find it, half the time. Just use google to search, and commence the search string with "priuschat". Google actually perpetuates lousy website search engines, they don't need to work, everyone just gives in and googles.
     
  10. xliderider

    xliderider Senior Member

    Joined:
    Apr 19, 2012
    7,842
    3,099
    0
    Location:
    Honolulu, HI
    Vehicle:
    2011 Prius
    Model:
    Three
    Post #46, on page 3 here:

    How can I mod the DRL to have it on at all time? (for 2013 models) | Page 3 | PriusChat

    Sorry, I don't know how to link to a specific post within the thread.

    And the install instructions for the oem foglights is here in the first post.

    2010 Prius OEM-quality Fog Light Kit Now Available! | PriusChat

    Where, specifically, it mentions where the rubber grommet is to push wires through the firewall is.
     
    #10 xliderider, Jun 30, 2015
    Last edited: Jun 30, 2015
  11. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,474
    38,106
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Reading Xlideriders' shopping list in post #4, you guys are going through a lot, to install something that's not mandatory, and going at it in the most difficult way. It's largely for the look I guess?

    In Canada, turn the car on, release the parking brake: the high beams come on at reduced brightness. That's the DRL. Turn headlights on, DRL goes off.
     
  12. xliderider

    xliderider Senior Member

    Joined:
    Apr 19, 2012
    7,842
    3,099
    0
    Location:
    Honolulu, HI
    Vehicle:
    2011 Prius
    Model:
    Three
    Yeah, I actually built my own highbeam DRL module to get that functionality on my 2011, which is the model year prior to the LED DRLs coming from the factory. It was pretty complex, 3 relays, diodes, etc. Cost me over $200 including all the trial and error materials, etc. Then I found a solid state module on eBay that did the same thing, and installed that. Link is in my signature below.

    My avatar pic is a full sun shot with the highbeam DRLs on.
     
    #12 xliderider, Jun 30, 2015
    Last edited: Jun 30, 2015
    Mendel Leisk likes this.
  13. Nobody123

    Nobody123 Member

    Joined:
    Apr 14, 2015
    160
    33
    0
    Location:
    United States
    Vehicle:
    2015 Prius Plug-in
    Model:
    Plug-in Base
    Thank you very much.

    On the post where it shows the post number, click on it. A link will pop up. Paste that link and it will link you straight to the post number.

    Example: In your post at the bottom right where it says "#10". Click on that and paste the link: 2012 GEN 3 Install Fog light Switch to keep DRL to Stay ON