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How to adjust halogen headlights

Discussion in 'Gen 2 Prius Main Forum' started by megatron, Mar 13, 2021.

  1. megatron

    megatron Junior Member

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    I have a 2006 Prius IV with halogen headlights. I’m trying to figure out how to adjust the headlights left and right. I found only one adjustment knob on the lens unit and that adjusts up and down, not left and right. Am I missing a second knob somewhere, or how do I adjust sideways?

    Any help would be greatly appreciated! Thanks!
     
  2. ChapmanF

    ChapmanF Senior Member

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    I don't think there is a horizontal adjustment, regrettably.
     
  3. dolj

    dolj Senior Member

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    There is a second adjuster that I presumed was for the left/right, but I haven't been able to confirm as you need a longer (> 10" (250mm) shaft #2 Philips screwdriver to reach it and I don't have one long enough. It is also more or less impossible to locate its position with the headlight installed. I just recently replaced my halogen lamps and had the enclosures out so made a note of how to locate them when the headlight enclosures are installed. There are raised lines on the black plastic part to indicate where to insert the screwdriver. The indication lines are in the same location right and left, but mirrored.

    The actual left/right adjustment screw is situated above and further inward. Attached are some images to help you visualize the location.

    You may be able to reach the adjusters without taking the front radiator trim cover off, but these images are with the cover off. You certainly can't reach the up/down adjuster with the cover in place.

    Prius Gen 2 RHS Headlight top adj Close Marked.JPG Prius Gen 2 RHS Headlight top adj.JPG.JPG Prius Gen 2 LHS Headlight top adj.JPG marked.JPG

    I hope this helps, let me know if you have any questions.
     
  4. megatron

    megatron Junior Member

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    Are you saying this is on the side of the headlight? I am having a hard time referencing where this location to insert the screwdriver is. Do you have pictures zoomed OUT some more so I can get a better point of reference? I don't see where I can insert a screwdriver anywhere on the housing.
     
  5. dolj

    dolj Senior Member

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    Look again at the left side image in my previous post. In the top left of the photo, that is the bottom of the engine bay fuse box. The silver bit below the line is the engine bay top rail.

    Look for that big clip on the light enclosure.

    Yes, the screwdriver slips in under and on the outside of the light enclosure, but it is very hard to see even where to insert the screwdriver. The setup is exactly the same as the left/right adjuster that you can see including the channel that guides the screwdriver to the adjuster wheel.

    Does this help?

    Prius Fuse box.jpeg

    The mark is mirrored on the other side.
     
    #5 dolj, Mar 15, 2021
    Last edited: Mar 15, 2021
  6. megatron

    megatron Junior Member

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    Thanks for the clarification. It is difficult to see behind the light, but I think I see what you are referring to. The issue is that there appears to be a black cover over the adjustment disc. I would have to pry that cover off in order to get to the silverish adjustment disc. But there is no way I can get back there to remove the cover without removing the entire headlight assembly first. Man, what a pain. For some reason, the up and down adjustment doesn't have a cover over it, but this left/right one does. Did you run into this issue?
     
  7. ChapmanF

    ChapmanF Senior Member

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    Page LI-83 in the 2006 Repair Manual shows only a vertical adjustment screw, nothing for horizontal. That matches what I remember from my Gen 1 and also my Gen 3.
     
  8. dolj

    dolj Senior Member

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    No, there is no cover over the disc and no disassembly is required. ChapmanF has pointed to the relevant section of the 2006 NA Gen2 which I have quoted below.
    The manual definitely makes no reference to any horizontal adjustment, and the image does appear that it might show no adjustment wheel is present, but these pencil sketch drawings are notoriously vague when it comes to some detail. However, in the image below I have marked a reference to position "B" where there is definitely an adjustment wheel on my headlight enclosures.
    Prius Gen 2 Headlight Marked.png
    It looks just like (A) and you get to it in a similar manner – you just need a very long-shaft #2 Phillips screwdriver to reach the wheel.

    Maybe this is another of the many difference between the NA market and the rest of the world.

    My apologies if I have wasted your time. Mea culpa.
     
    #8 dolj, Mar 15, 2021
    Last edited: Mar 15, 2021
  9. megatron

    megatron Junior Member

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    Hi again,

    I gave up trying to peak behind the lights so I decided to just rip both headlight modules out from the car to have a better look at the backsides.


    The silver uncovered knob is the one for the up and down adjustment. But if you look carefully at the individual pictures, you can see the other adjuster covered up by a black cover with slots in it. That’s the cover I was talking about. Now, it’s easy to remove and adjust it out of the car, but obviously, I want to adjust this when the lights are installed in the car to get proper adjustment. That’s the hard part. How would I do this?