2007 HID headlight where nothing will fix it including all new Toyota ballast and bulbs

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Bill and Cindy, Dec 13, 2017.

  1. Bill and Cindy

    Bill and Cindy New Member

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    We have a 2007 Prius with 167K miles on it and have experienced headlight issues over the years. Each time they would begin to go out intermittently and after turning them on and off would work again for a time. Here is our history with the issue.
    Replaced ECU on both headlights under warranty 8/2009. This took care of the issue for many years.
    I had to replace both ballasts and bulbs Dec. 2014. Did this myself after watching YouTube videos. Ordered OEM parts marked Toyota from eBay which looked identical to parts Toyota had installed in 2009.
    I replaced passenger side ballast (ECU) and new bulb June 27, 2017 after having the intermittent issue return on the passenger side only. Got OEM parts marked Toyota through Amazon. This didn't fix it and we have continued having it go out intermittently. Since it was intermittent and on the passenger side I lived with it.
    Driver's side headlight went out completely and wouldn't turn back on a few weeks ago. We have a community college that has an auto repair program and I was able to get it into their electrical class. A fuse had blown. Drivers side ballast was showing a dead short and passenger side was showing an intermittent short. They replaced both ballasts (ECU) with Toyota dealer parts on Nov. 29, 2017. Found out they were still not working, but having the intermittent issue that evening on the driver's side and uncertain about the passenger's side. Dec. 4 they replaced driver's side headlight with Toyota Bulb but we are still having the intermittent issue.
    When I call Toyota service, one dealer claims that they have never seen this issue and the other one knows it is an issue but would do what we have already done.
    We have heard of the wiring harness being an issue, but the school looked it up and it would be about 3K their cost for the harness as it is a one piece wiring harness for the entire front end and it would be a major thing to replace it (bigger than they would want to get into).
    At this point we are trying to avoid driving at night and when we do also have the fog lights on. We are always checking to see how many lights are shining into the bumper in the car in front of us at stops and turning our lights on and off to have the driver's side go back on.
    Has anyone had this issue and not been able to get it corrected through these measures? Is there something else we are missing? This is getting old and costly as well as time consuming. Any suggestions would be greatly appreciated. Other than this, the car has been wonderful and we enjoy driving it.
     
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  2. valde3

    valde3 Senior Member

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    I just don’t understand why they would need to replace the wiring harness rather than just fixing the problem in the harness.

    How often does it act up? Just measuring it when the problem is present should reveal the actual problem.
     
  3. 2k1Toaster

    2k1Toaster Brand New Prius Batteries

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    Basically everything you describe at first is just a bad bulb. They do die, and when they do, they just go out intermittently. Replacing the "ECU" and then ballasts seems unnecessary, the bulb itself was the issue.

    But now with fuses blowing, that is only either a really bad bulb, a bad ballast, or bad wiring. You have replaced the bulb with a new one. You've replaced the ballast with a new one. That only leaves wiring assuming the other parts are good.

    It is really easy to power these on the bench. Just get your ballast out, plug in the bulb, and power the ballast directly from a spare 12v battery. It should just light right up. Bear in mind touching the bulb with your fingers even just once, you doom the bulb to a terribly short service life since the oils in your skin transfer to the bulb and then make it hot.

    If the bulbs and ballasts work on the bench, then I would order (or make) another relay powered wiring harness and just bypass the original wiring. About $50 in parts if you buy it, $10 if you make it, and a half hour of work to completely bypass. You may just have had a rodent chew threw some wiring.
     
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  4. Bill and Cindy

    Bill and Cindy New Member

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    Bulbs were changed each time prior to replacing ballasts. Bulbs were never touched. As far as bypassing the original wiring; The ECU comes with a new plug to power it but I have never changed it as it seems intact. Not sure about outside the headlight unit as I have never unwrapped it to see how it looks. Maybe my next project.
     
  5. fred246246

    fred246246 New Member

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    I am having the same issue with the headlights dying after a couple minutes of working. Dealer says HID must be replaced with HID AND the ballast otherwise the problem will persist. Estimate for that repair is $1,000.

    Can the entire headlamp assembly be replaced with an LED version or does it have to be the factory original HID assembly?
     
  6. Kevin_Denver

    Kevin_Denver Active Member

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    There are projector headlight kits for the 2nd gen that are $300-400. The light output of projector headlights are usually okay to put LED replacements in, as they will have the sharp cutoff needed to keep from blinding other drivers. You'll still want an LED kit that mimics the location of the halogen bulbs.

    Otherwise, you shouldn't put LED replacement "bulbs" in halogen or HID headlight reflectors.
     
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  7. Soulbarer

    Soulbarer Junior Member

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    ----USA----
    I commented on another thread about HID to halogen conversions. HIDs can be great, but the Gen 2 Prius had a recall because they failed so often. If you are out of warranty (I have a 2006 with 220k miles so obviously), addressing this problem gets very costly.

    After lowering the bumper with a 10mm socket (an extension or deep socket helps) not difficult - half of it pops off once the bolts are removed, I swapped out the assemblies for new halogen ones from Amazon, $120 for the set

    I purchased 9003 halogen bulbs and the halogen socket/harness from O’Reilly but they are on Amazon, roughly $20 for all

    After removing the dust cap from the old assemblies, I cut the black-wrapped wires to the high beams (goes to a little motor on the HID) and cut the white-wrapped wires going to the ballast for low beams. Then I connected the ground from each to the new harness ground wire, and the red bright supply to the red harness, and the red low beam supply to the blue (some harnesses have different colored wires so you’ll have to expose them to see which prong they go to).

    The lights look great and have functioned perfectly with great visibility for a couple months now. I suppose I may get dust or moisture inside the lights eventually as the new assemblies did not come with a dust cover, but for now I have the custom combination of halogen lights plus still have fog lights!

    I am not the handiest guy, but this was pretty easy and didn’t take too long, once I thought it all through. I also like the shiny new assemblies. Hopefully this helps someone else with an older Prius that is experiencing the ongoing HID headache. Good luck!

    prius 1.jpg prius 2.jpg prius 3.jpg prius 4.jpg
     
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  8. oil_burner

    oil_burner Active Member

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    I'm not sure why you guys are bothering to replace them with geniune toyota parts when those are noteably overpriced and faulty to begin with anyway. The aftermarket for HID bulbs and ballasts are huge, my last set of bulbs and ballasts cost under $100 to me and would easily plug in to your system with a little wiring knowledge. There is no need to be tossing out a good HID system for a crappy LED or halogen.
     
  9. Soulbarer

    Soulbarer Junior Member

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    Get awesome lights for a $10,000 car, not a Gen 2 Prius.

    For a car with over 200k and a kbb value under $3000 it isn't worthy of HIDs imho. For most of us it's just a grocery getter or commuter. I previously did try an aftermarket ballast and supposedly higher quality bulb with the flickering issue returning, and got tired of the money pit. Halogens are old reliable and great for a car that's long-gone out of warranty.
     
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