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Frequent Failure Passenger Low Beam

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Joe Mc, Oct 4, 2022.

  1. Joe Mc

    Joe Mc Junior Member

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    2011 Prius.
    • May 2021 the "believed to be original" passenger low beam failed. I replaced both left and right low and high beam lamps with Sylvania whatever the super duper blinding lamps are called (were not cheap).
    • Feb 2022 passenger low beam failed. Replaced both low beam lamps with Phillips whatever super duper...
    • Sep (week of the 18th) 2022 again with the passenger low beam???
    Any idea what might be causing this "just the passenger low beam" frequent failure? upload_2022-10-4_21-49-12.gif
    1. I know the car's history since new, it was my father-in-laws car - never in any type of fender bender, a few scrapes on the lower front bumper cover with those concrete parking lot stopper things and same with curbs. He passed at the age of 91 a few years back. When we acquired the car it had like 45,000 miles. Now 108,000 miles.
    2. The wires at the lamp plug are in excellent shape, no failed insulator, not rubbing anywhere and the plug itself is like new.
    3. Just don't get it, why just the right low beam?

    Appreciate any tips or thoughts that I could use to look into possibilities?

    Thanks,

    Joe
     
  2. Tombukt2

    Tombukt2 Senior Member

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    You're using filament bulbs gas inside of a glass tube with a wire I would say come on man bring it into the 21st century or whatever we're in and get some LED cob type headlights aim them correctly and never discuss this again but if that's not a thing just keep going to Walmart or AutoZone and buying the super duper blinding halogen wire gas bulbs. It is pretty simple I don't think it's your car causing the bulbs to burn their filaments when you look at the bulb after replacement do you see the filament broken? Are you touching the lamps with your fingers when installing you shouldn't be and if you do you need to wipe them off with like alcohol or something that will destroy the oil from your fingers on the glass that you touched have a big plastic in there to be touching Don't touch the rest of the mess basically Good luck. LED cob headlights are your friends
     
  3. ChapmanF

    ChapmanF Senior Member

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    There were around 390,000 2010s and 2011s with the eats_low_beams property, which results from a wiring harness that does not drop the system voltage quite enough before delivering it to the low-beam headlight bulbs. Toyota issued a technical service bulletin, T-SB-0204-12, instructing dealers to splice in additional wiring segments (part number 04007-52147), which shave about three fifths of a volt off what's delivered to the low-beam bulbs. (Headlight bulbs are generally constructed for 12.8 volts, as marked on their packages, and that assumes the car's wire harness will be dropping the voltage a little. A Prius normally operates around 13.6 to 14.8 volts, and filament bulbs are extremely sensitive to voltage. Overvoltage makes them somewhat brighter, somewhat whiter, and much, much shorter lived.)

    At first, when Toyota issued that service bulletin in 2012, you would have to pay for the repair if your car had that issue. The repair involved two of the 04007-52147 wire assemblies (one for each side) and labor to install them.

    Later, they announced a warranty extension (customer support program ZHB) that would make the same repair for free if your car exhibited the problem. ZHB would replace both your low-beam bulbs and install both voltage adjustment harnesses, even if you had only noticed the issue on one side. ZHB was good for unlimited miles, but only until 31 October 2019, so, regrettably, that coverage is gone, and it's back to paying out-of-pocket to get those adjustment harnesses installed.

    If you are living with a Prius that has the eats_low_beams property and hasn't been fixed, you are doing yourself no favors by buying the super duper bright filament lamps. Those are already built to trade off lifespan to get more light output, compared to the standard lamps, and in an eats_low_beams Prius they live brilliant but fleeting lives like beautiful fireflies, and you will get so good at replacing them you can do it in your sleep.

    The best filament bulbs you can buy for an unfixed Prius are the original bog-standard basic ones. In most auto stores you kind of have to look for those. The super duper high-profit-margin bright ones will be hanging at eye level right in front of your face, and the standard ones are probably hanging on pegs down by your ankles.

    The guy who sold me my 2010 had put super duper ones in, and they had burned out by the time I looked at the car. :) I did buy the two 04007-52147 harnesses, but never ended up putting them in, because after putting standard bulbs in rather than the super duper ones, they were still going strong a couple years later and I decided that's good enough for me.

    LED low beams of course sidestep the issue completely, if you can find any that (a) really are DOT compliant for on-road use and (b) don't ruin your radio reception.
     
    SFO, Joe Mc and PriusCamper like this.
  4. Tombukt2

    Tombukt2 Senior Member

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    Mine are Tuv std I believe Hella Germany . In wife's 2010 late car. I removed running or working basic low beams the hella cob LEDs made a huge difference in the Prius fake projectors which I do like I don't care for that electronic shuttered projector business keep it simple and cheap. And I have bright cob LEDs in the high beams too and when you put those on you're really pissing somebody off probably I think I've used the high beams two or three times in the time I've ever driven the car and they are aimed correctly as far as we can tell
     
  5. Joe Mc

    Joe Mc Junior Member

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    ChapmanF,
    Thank you for your reply. Exactly what I was looking for = the "why" this happens and "what" to do to correct.
    When I purchased replacement lamps (@ NAPA) the "counter guy" gave me the super dupers, I'd have been just as happy with the standard lamps but figured "what the heck". Now I know "what the heck" and will utilize the super dupers until they fail again (returned 1 bad lamp in the 2 pack and received new 2 pack, so I've got a spare) then revert back to standard.

    Tombukt2,
    Thanks for your reply as well. Totally understand the (probably) most reason new lamps fail is due to people touching the glass lamp.

    Unsubscribing
     
  6. TMR-JWAP

    TMR-JWAP Senior Member

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    I replaced both left and right low and high beam lamps with Sylvania whatever the super duper blinding lamps are called (were not cheap).

    This alone will cause a loss of operating hours. With Halogen bulbs, the brighter they are, the quicker they die. I believe every display center I've seen with bulbs has a chart showing expected life hours, and the bright ones are pretty low....

    I'm approaching 6 years on a set of OEM Phillips 4300k HID's I installed in my 2007 about a week after I purchased it.