High Beams Problem

Discussion in 'Gen 4 Prius Care, Maintenance and Troubleshooting' started by tigerpilot, May 28, 2026 at 2:12 PM.

  1. tigerpilot

    tigerpilot Member

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    2016 Prime. I have an issue with my high beam switch. If I push the lever for the momentary high beams no issue. If I want them to stay on, I pull the lever but nothing happens. No indicator on the dash and no high beams. I thought it might be one of the small relays in the engine fuse box but they both test okay. I will appreciate any help on this. TIA. Don in rainy Naples.
     
    #1 tigerpilot, May 28, 2026 at 2:12 PM
  2. ChapmanF

    ChapmanF Senior Member

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    Did you swap pull ⇄ push when you wrote that? Or is that really how the 2016 works?
     
    #2 ChapmanF, May 28, 2026 at 4:49 PM
  3. tigerpilot

    tigerpilot Member

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    Yes, the 2016 uses the headlight switches off of the steering wheel. Pull for momentary on and push for on all the time. The relay curious thing is if the ignition is OFF, then it works perfectly. Once you push the power button the “on always” does NOT work. With the ignition OFF and everything is quiet I can hear the relay under the hood closing.
     
    #3 tigerpilot, May 28, 2026 at 7:34 PM
  4. ChapmanF

    ChapmanF Senior Member

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    Oh good, that's the same way the earlier generations all worked. In your post #1 you wrote push for momentary and pull for on all the time.

    The way you describe the behavior being different when the car is ON is kind of peculiar. I don't have any sure-fire ideas.

    In gen 3 cars built with daytime running lights, the DRLs worked by sharing the high-beam headlight bulbs (halogen, in gen 3), running them at reduced power for DRL duty. There's a place where a behavior difference between car on and car off could come in.

    I don't know any of the details of gen 4 DRLs though. Does you car have DRLs?
     
    #4 ChapmanF, May 28, 2026 at 7:43 PM
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