Different Headlight Problem: Both lights out, not intermittent

Discussion in 'Gen 2 Prius Technical Discussion' started by azapplewhite, Sep 3, 2008.

  1. azapplewhite

    azapplewhite Junior Member

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    OK, Newbie here but I promise I searched the other threads first!

    I have a 2005 Prius with 58K miles. I replaced one headlamp about 5K miles ago. Last night I went out to run an errand and BOTH headlamps (lo beams) were out. The high beams work fine. They were working perfectly before this, none of the intermittent issues described in the other threads with the HED lamps.

    I checked the fuses and they are both OK (who knew they have individual fuses for each beam!?). I could replace both bulbs but it seems unlikely that they'd both die at the same time, especially when one is almost brand new.

    Has anybody out there encountered this before or have any troubleshooting suggestions? Aside from the on/off switch, are there any other elements of the system that have single point failures that could take out both lamps?

    And apologies in advance, how do I tell what kind of lamps I have? It was a base model, does that mean it does NOT have the HED lamps?

    Thanks, Anthony
     
    #1 azapplewhite, Sep 3, 2008
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Hi Anthony,

    The sure way to tell what headlamps your car has is to note whether you have fog lamps or not. If not, then you have halogen headlamps.

    If you have a digital multimeter available then you can troubleshoot this problem. I suggest that you download the headlight wiring diagram for your car from techinfo.toyota.com which is a subscription website.

    Since you say that both high beams work and both low beams are out, then my guess is that the dimmer switch mounted to the steering column has failed.

    Good luck.
     
    #2 Patrick Wong, Sep 3, 2008
  3. Celtic Blue

    Celtic Blue New Member

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    Is that dimmer an inexpensive/easy swap (as opposed to a major column assembly)...or would it makes sense to exchange connections at the switch with the wires for the brights as a workaround?
     
    #3 Celtic Blue, Sep 3, 2008
  4. qbee42

    qbee42 My other car is a boat

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    He has halogen lamps. The HIDs don't have low and high beams: one capsule does both.

    Tom
     
    #4 qbee42, Sep 3, 2008
  5. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Well, it is necessary to remove the driver's air bag, then remove the steering wheel, then the steering column cover. At that point the turn signal switch assembly with spiral cable assembly can be removed.

    The turn signal switch assembly is a large part, and includes both switch stalks. I don't know whether it is possible to replace individual switches within that assembly.
     
    #5 Patrick Wong, Sep 4, 2008
  6. azapplewhite

    azapplewhite Junior Member

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    Epilog: Different Headlight Problem: Both lights out, not intermittent

    Thanks for all the inputs.

    Well, it turns out that both bulbs were burned out and that was the extent of the problem. Don't know how I managed to just get ~5K miles out of the new bulb, I guess I wasn't careful enough about touching the bulb during installation!
     
    #6 azapplewhite, Sep 8, 2008
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