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Auto Headlight Issue

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by steveholtam, Jul 25, 2008.

  1. steveholtam

    steveholtam Junior Member

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    Hello all. I have accidently ran my 12v battery dead and near dead a few times, and I just figured it out. Each time, I have gone out to my car and cracked the windows when the shade hits my car so its not so hot after work. Each time I was wondering, how could simply turning on the car for a few seconds and rolling each window down a couple of inches possibily drain the battery? I figured I had a crappy battery.

    Well, this morning I did the above, and a co-worker notified me that my head lights were on. Huh? I went out, and yep, they were on. I had left my headlights in the Auto position, and even in the light of day, my headlights thought it was dark enough for me to need them.

    Two questions!

    Can the brightness senitivity be adjusted?

    And, how come the lights do not turn themselves off when the car is locked up after a few moments? Don't most cars do this nowadays? The Prius should be smart enough to say, hey, the battery is draining dead because the headlights (or anything else) are on.

    Thanks!!!

    Steve
     
    #1 steveholtam, Jul 25, 2008
  2. chich2000

    chich2000 Junior Member

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    do the 08 have auto light? I have an 06 and at the time the US Prius lacked that feature. Anyways if it does maybe the shade could have an effect but it shouldn't be that sensitive. I have auto light in my highlander and the lights do come on when I put a sunshade on the windshield or when I pull in to the garage but never from the shade of a tree.
     
    #2 chich2000, Jul 25, 2008
  3. steveholtam

    steveholtam Junior Member

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    I think so. Isnt the last pip on the light control stick Auto? I think the sensor is on the front facing side of the rear view mirror. At least there is a little white sensor looking thing there...
     
    #3 steveholtam, Jul 25, 2008
  4. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Hi Steve,

    1. Is the car IG-OFF when you leave it (so that the MFD is dark and no warning lights appear on the dashboard)

    2. Unless your car is very different from the 2G Prius that I know, there is no auto feature where the headlights will turn on based upon the presence or absence of ambient light. If the headlight switch is left turned on, the headlights will turn off automatically when you make the car IG-OFF and leave the car via the driver's door. However if you exit via a different door the headlights will remain on.

    3. The center rear-view mirror has an autodarkening feature so that bright headlights at night behind you in principle should not blind you.

    4. The Prius is not smart enough to determine that the 12V battery is being drained, and cut power accordingly.
     
    #4 Patrick Wong, Jul 25, 2008
  5. qbee42

    qbee42 My other car is a boat

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    The U.S. model of the Prius does not have auto headlights. That could explain why they were still on.

    The U.S. model will shut off the headlights if you open the driver's door after you have powered off, but there are several ways to accidentally beat the auto-off, so you need to check them each time.

    Tom
     
    #5 qbee42, Jul 25, 2008
  6. steveholtam

    steveholtam Junior Member

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    Thanks all! I did exit out the passenger door, so that explains why this is happening. I guess I just got used to my last five cars that would protect me from stupidity! Of course they only got 14mpg, so I'll just remember to turn the lights on and off the old fashion way.

    I wonder if anyone has created a mod to turn the lights off based on outside darkness?
     
    #6 steveholtam, Jul 26, 2008
  7. passnthru

    passnthru Average Member

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    #7 passnthru, Jul 26, 2008
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