Possible to add 'Factory' fog lights?

Discussion in 'Gen 4 Prius Accessories and Modifications' started by pioneer815, May 2, 2025.

  1. pioneer815

    pioneer815 Junior Member

    Joined:
    Sep 28, 2023
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    Location:
    Elsmere Kentucky
    Vehicle:
    2021 Prius
    Model:
    LE
    I'm looking to install the factory fog lights to my 2021 LE. I already understand I need a new bottom grill with the fog light cutouts along with the wiring harness for said fog lights. My biggest question about this is, is it possible to change out my headlight control arm for one with the fog light selector? I found one on eBay but noticed the connector has 3 more prongs than the connector on the base arm (the one I have installed) and that the plug itself doesn't have wires ran to these prongs. This honestly might be the deal breaker about going through with buying the parts if this isn't possible. (I already know that 'the fog lights don't add much and they aren't worth it' but I don't care, I like the look and idea of them) first image is of my currently installed arm, second is the one with the fog light switch. Screenshot_2025-05-02-03-07-04-04_40deb401b9ffe8e1df2f1cc5ba480b12.jpg Screenshot_2025-05-02-03-06-48-36_40deb401b9ffe8e1df2f1cc5ba480b12.jpg
     
  2. davev1pa

    davev1pa Junior Member

    Joined:
    Jul 23, 2021
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    Location:
    Lincoln,NE
    Vehicle:
    2016 Prius
    Model:
    Two Eco
    Tag along to this thread...not trying to hijack this thread....2016 eco 2 base....can I add fog lights? Are there connectors already on the harness? Is a switch easily installed? Are there aftermarket lights available and which ones have been used?
     
  3. ChapmanF

    ChapmanF Senior Member

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    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    Looks as if the connector housing per se is the same, and your harness just lacks the wires going to the three unused positions. You can look up the part numbers of 'repair terminals' for that connector in the wiring diagram. This page has links that will show you how:

    Toyota Service Information and Where To Find It | PriusChat

    You'll want to look in the wiring diagram anyway to find out which wires are missing in your model and where you need to run them.

    When I added fog lights to my gen 3, I had to run a wire from the fog pin on the new switch stalk to the fog input pin on the body ECU, and run a wire from the fog output pin on the under-dash fuse box, through the firewall, to the connector where the bumper-cover harness plugs in. From there I just used a factory-with-fogs bumper-cover harness. I used the factory grill openings but Morimoto LED fog lights; they work pretty well. And because they are LEDs, I could get away with adding a 3-amp fuse in the 'fog' slot of the fuse box, instead of the 10-amp or whatever it says on the lid. The fog light indicator on my instrument cluster never comes on, but the lights do work.

    Anyway, all those details are for gen 3. You'll just have to study the wiring diagram to find out what your generation needs.
     
  4. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
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    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    FWIW, I have the factory fogs on my gen 3, from the factory. Once in a blue moon I'll turn them on, say driving narrow road with no streetlights, or fog, and can barely discern the difference. They're very anemic. Look nice, anyway.

    Maybe I could try swapping out the lights themselves, but hardly seems worth it, so rarely need them.