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Low beam Headlights have poor illumination

Discussion in 'Gen 3 Prius Technical Discussion' started by Bobulator, Dec 4, 2023.

  1. Bobulator

    Bobulator Junior Member

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    Vehicle:
    2010 Prius
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    III
    2012 and 2013 Prius II in our household, and both have terrible illumination from the low beams. I regularly polish the plastic cover, makes little difference. Did the H9 upgrade on one, helped a little, did a LED upgrade on the other, no real improvement. However, the high beams on both are like photon torpedos in comparison, so I don't think there are issues with the headlight covers. I'm wondering if the round internal diffusers are a source of the problem? Can they be replaced or changed? Any other thoughts?
     
  2. Tombukt2

    Tombukt2 Senior Member

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    Wow the fake projectors on our generation 3s seem to work very well We have LED aux beam brand S1 series their latest cob LED and h 8 or h11 I can't remember which is which and they go like gangbusters we've not had any problems even my blind other half said she can see better than she ever has. And her outer lenses are starting to cloud I have cleaned them when we got the car it's time to do it again but the fake projectors seem to have great cut off and everything works wonderful and yes the high beams with LEDs in them are torpedoes they'll blind everybody We almost never have to use them.
     
  3. ASRDogman

    ASRDogman Senior Member

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    You would have to take the whole thing apart, without breaking it. Not gonna happen! :)
    Check for a poor connection at the connector, and for a back ground....

     
  4. Mr. F

    Mr. F Active Member

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    Vehicle:
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    Not all LED replacements are created equal. The $30-50 replacements are unfortunately just not very bright to begin with. The chips generate a lot of heat, and without good thermal management even the brightest ones will ramp down light output quite rapidly. You'll need to pick one with a good combination of brightness and thermal management to see a difference.

    How well the polishing was done also matters. Walmart offers headlight restoration services for ~$25 a pair, and they've managed to get the covers crystal clear on the two occasions I've used them (on two different vehicles). What I was able to achieve at home was very far off the mark.

    Of course, all this is assuming there is nothing actually wrong with the headlight assembly other than surface oxidation.
     
  5. Tombukt2

    Tombukt2 Senior Member

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    Yeah on the headlight kits now you need a good one like the mothers or the turtle wax with the actual sanding business being used I do mine with the small electric drill like device not too fast but I'm literally sanding the plastic down that's why I like the factory headlights they're nice and thick You got a good bit you can sand down and then you run through the three papers till you get to the 1200 or whatever and so on and so forth and they come out looking pretty spiffy but you have to take the time to do the sanding properly but you can get them very clean If you've got replacement fakes in there You need to clean them with the not sanding type cleaner and just do it more often You can buff them but not really sand them because they're so thin You can just put your finger on them and tell the difference between those and the factory and then if they're too far gone and they're not original just replaced them they're cheap enough now.