Why does this Head light bulb never come on?

Discussion in 'Prius c Main Forum' started by 9Shenandoah, Dec 14, 2025 at 5:32 PM.

  1. 9Shenandoah

    9Shenandoah New Member

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    upload_2025-12-14_14-30-9.png

    I noticed today no matter what I do this lamp doesn't come on (during the day).
    I swapped it with a new one and still nothing.
    Is it because I am testing it during the day?
    I turned my headlight switch to all positions and tried high beam also
     

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  2. ChapmanF

    ChapmanF Senior Member

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    I believe that is the bulb for high beam.

    If it doesn't come on when high beam is selected, even with a known-good bulb, then there must be a problem elsewhere.

    What happens with the corresponding one on the other side of the car?
     
    John in Vermont and BiomedO1 like this.
  3. 9Shenandoah

    9Shenandoah New Member

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    I think it comes in automatically at night.
     
  4. ChapmanF

    ChapmanF Senior Member

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    That would surprise me.
     
  5. BiomedO1

    BiomedO1 Senior Member

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    NOPE; do you know how the high beams on a car functions?????o_O:rolleyes::sleep:

    If the blue high beams symbol in your dash cluster is lit; that lamp should be ON.:sick::whistle:
     
    #5 BiomedO1, Dec 15, 2025 at 11:39 AM
    Last edited: Dec 15, 2025 at 12:11 PM
  6. Mendel Leisk

    Mendel Leisk MMX GEN III

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    Canadian spec 3rd gen Prius, and I’d suspect Prius c as well, turn the high beams on at half-brightness when you’ve got headlights off, essentially they’re the daylight running lights.

    Being in Washington State, any chance it’s a Canadian spec car?

    also, do you still have the old bulb? How’d it look?

    Maybe old one burnt out, new one is defective, incompatible, or somehow not installed right?
     
  7. BiomedO1

    BiomedO1 Senior Member

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    DRL are not required in the lower 48 and is controlled by the headlamp stalk. I don't recall on my old 2012, but on my 2021 you can leave the head lamp in DRL mode - instead of OFF. Even then; you'll need to place the car into gear BEFORE they will turn ON. After that, they will remain ON until you shut-down the car.
    I believe all that is outlined in the OPS manual......

    As I recall, the high beams was easy to get to, it was the low beams that was a squeeze. I replaced all mine with LEDs, They had a very fast flash, shimmer in DLR - so you don't go unnoticed. Once headlamps was engaged, shimmer went away, so I could only conclude it was the low voltage solid state relays cause this. Decided to; too lazy to rewire to correct this - It didn't burn out the bulbs or cause any electrical problems for the 5 years of operations, before someone totaled it out.
     
    #7 BiomedO1, Dec 15, 2025 at 11:58 AM
    Last edited: Dec 15, 2025 at 12:26 PM