Tail Lights On in the Morning

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Astro33, Dec 9, 2006.

  1. Astro33

    Astro33 New Member

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    I woke this morning to find my 2004 hatchback sitting in the driveway with the top (red) portion of the tail lights illuminated.

    The air temperture was about 20 degrees F.

    I went outside, started the car, and looked to see if any light switches were left on. (They were not.) I cycled the headlight switch on and off a few times, but the top tail lights remained on. I turned the car off, and the lights remained illuminated. So, I turned the car back on and consulted the manual.

    After the car had run about 10 minutes, the tail lights extinguished on their own.

    I haven't re-read every word in the manual, but so far I haven't figured what was happening.

    Any ideas out there?

    Thanks!
     
  2. Beryl Octet

    Beryl Octet New Member

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    <div class='quotetop'>QUOTE(Astro33 @ Dec 9 2006, 07:46 AM) [snapback]359669[/snapback]</div>
    The angle of the sunlight making them look like they are on? Don't laugh, I was walking to my car in the parking lot the other day, about the time of sunset, and I was convinced that I'd left the lights on all day because of the way sunlight was reflecting out of the tail lights.
     
  3. Astro33

    Astro33 New Member

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    Well, it wasn't that...this was before sunrise and it was dark outside. The lights were definitely on.

    Thanks~
     
  4. Beryl Octet

    Beryl Octet New Member

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    <div class='quotetop'>QUOTE(Astro33 @ Dec 9 2006, 10:38 AM) [snapback]359699[/snapback]</div>
    Bizarre indeed. Poltergiests? A stuck relay?
     
  5. Astro33

    Astro33 New Member

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    I can't imagine a stuck relay, but I suppose that's possible. (I opened the hatchback to remove stuff when I parked last night. The lights were NOT on when I locked the car last night.)

    But, I'd rather a stuck relay than a failing computer module...
     
  6. Tom_06

    Tom_06 Active Member

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    <div class='quotetop'>QUOTE(Astro33 @ Dec 9 2006, 11:03 AM) [snapback]359711[/snapback]</div>
    The top portion of the tail lamp assembly is the brake light (top to bottom is brakes, turn signal, tail light). I'd suspect the switch activated by the brake pedal. Since it is temperature related, heating things down there with a hair dryer when it happens again would be one way to troubleshoot it. Or try wiggling and applying and releasing the brakes without starting the car. Maybe the adjustment on the switch is such that breathing on the brake pedal makes them come on and the cold flexes things enough to activate them.

    - Tom
     
  7. Astro33

    Astro33 New Member

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    That's a great tip. Thanks~