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Extra help with fog light wiring

Discussion in 'Gen 3 Prius Accessories and Modifications' started by The Phoenix, Oct 2, 2019.

  1. The Phoenix

    The Phoenix Member

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    I have a 2010 Prius and ordered an aftermarket fog light kit, they get installed right under the turn signals. I am much more mechanical adept than electrically adept. So I had no problem installing the lights themselves into the bumper running the wire up into the engine compartment. Now the other wire harness has two 12 volt supply wires an additional ground and relay. I am sinking one supply is for the small light on the switch the other supply is for the power to the lights themselves. I have changed the bulbs to LED bulbs don't believe I need the relay going to figure out simple way wire this into the cabin into the switch. I have referenced a PDF file from priuschat about fog light installation but it is not from the exact same kit. Any suggestions or ideas are welcome. I will include the picture the company sent me when I asked for wiring clarification. Color Harness Diagram_557334958577545.jpg
     
  2. PriusCamper

    PriusCamper Senior Member

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    I'm not clear on your question, but if you want to run the fog lights off a switch on the dash than one end of that switch connects to the trigger wire and then the other end of the switch connects to chassis ground. As for the 12v power wire with the fuse... That can connect direct to the battery if you want lights to work when car is shut off, or run it to a 12v wire that only has power when car is on. You can test for this with a cheap auto test light, which is a probe with a light bulb in it with one end attached to ground and the other end attached to whatever you poke with the probe to see if it lights up... You might be able to find the power wires for fog lights in the harness, or you can tap into a different wire as long as it can handle pumping more electricity than normal. But again I'm not sure what your question is?
     
  3. The Phoenix

    The Phoenix Member

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    Sorry about the word errors in my previous post. I am THINKING that the two wires that need a 12v supply are for the fog lights themselves and than the light on the switch itself. I am trying to run the wires in to the cabin and into the switch as simply as possible
     
  4. PriusCamper

    PriusCamper Senior Member

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    That switch would be easier to thread through an existing hole w/rubber grommet in the firewall if you could unplug the switch and just feed the wires through...
     
  5. The Phoenix

    The Phoenix Member

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    I apologize for not being more clear in my question, but I will say everything you said is making sense, although I am not clear about what a trigger wire does or how it works and if its necessary to make my fog lights work, as far as connecting the wires do I want to do that all behind the dash or do I want to use the fuse box in the engine compartment. On a previous vehicle I used an add a fuse and connector the main power to the fuse pannel that's beneath the steering wheel. So with all that I am not sure if I have a specific question but just trying to gather more information, to understand how I can do it.
     
  6. PriusCamper

    PriusCamper Senior Member

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    Yea, I kinda explained that wrong... Looks like there's two trigger wires... One is the switch you put in the dash and the other you splice into parking light wire, but it depends on what you want. I used to have a VW rabbit as teenager and the fog lights weren't connected to the rest of the lights on in the car, just a simple switch that would work as long as the car was running or in accessory mode.
     
  7. The Phoenix

    The Phoenix Member

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    I will definitely have to take some pictures when I get home from work. I would like to be able to only push one wire though, and I think I would have to do some cutting not just disconnecting and that's what I'm unsure of. I think I need to dissect the wire harness and use what I need where I need it
     
  8. The Phoenix

    The Phoenix Member

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    Yes that's the whole part I'm not understanding, and honestly I feel kind of dumb about it. I dont understand why I have to tap into a 12v power source twice
     
  9. PriusCamper

    PriusCamper Senior Member

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    Well... Sometime you'll want to drive without the fog lights on... So that switch in the dash will prevent those lights from coming on, even when the green trigger wire is told to turn the lights on. You don't have to wire it this way, but that's the options they designed it with.