Headlight Water & Condensation leads to HID Ballast Failure

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by bikr357, Jan 12, 2013.

  1. bikr357

    bikr357 Plugged in Member

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    This is a long post, for instructions on DIY HID ballast removal w/o cutting wires or plastic (it is possible), skip to the end.

    I over the past month I've noticed condensation inside the driver's side headlight assembly on my wife's '09 Touring. More recently I noticed that the headlamp was burned out. So today I set about trying to figure out what was going on since the headlight assembly has no apparent exterior damage which would allow water to enter the assembly.

    Removing the headlight was not terribly difficult, I just followed the steps shown in this video posted by luscious garage.



    However, replacing the lamp didn't solve anything and left me puzzling to determine the root of the problem. By swapping lamps between headlights I confirmed that I did NOT have a failed lamp issue. So at this point I figured I'd remove the cover plate at the bottom of the headlight assembly covering the light ballast. Its the one with the label "Computer, Light Control" and the yellow DANGER WILL SHOCK, BURN OR CAUSE DEATH" [note: I did this with the head light assembly removed from the car and disconnected from power]

    What I discovered was that the HID light ballast is located at the bottom of the headlight assembly, with the back of the ballast open to the interior of the assembly. If moisture collects in the assembly it ultimately ends up puddling around the ballast which then causes corrosion and ultimately failure, as was our case. Honestly what was Toyota thinking, putting the most critical and expensive component of the HID system in a location where when there is a breach in the headlight seal the water collects around an electrical component generating 25,000 volts when it is energized! No wonder HID's in Gen II's have such a reputation for failure. In my opinion this is a DESIGN FLAW. However ranting on Toyota's designer's or Toyota's refusal to accept responsibility for the headlight seal failure (sorry a 3-Yr/36K mile warranty on this issue is just long enough to ensure the failure will occur outside the warranty term) or this inherent flaw in the HID system isn't the true purpose of this post.

    Turns out there are no clear instructions on how to remove the ballast and more specifically snake the lamp connector around the reflector and remove it out of the ballast opening (not even in the service manual). One could just cut the wire, but then one is left with the problem of how to get the new connector and wiring harness back in. It appears from a forum search that others have gone this route and resorted to trimming plastic or disassembling the wiring connector and then reassembling it [which I wan't to keen on since this is the connector that transmits the 25,000 volts]. So here is how I solved the connector removal puzzle.

    Do this with the unit removed from the car and disconnected from power. If you have any reason to believe there might be a residual charge in the ballast, do not proceed.

    So here is the ballast, wiring harness and connector (upper right) once it was removed. The connector is what is such a problem to remove past all the obstructions inside the headlight assembly.
    [​IMG]

    Note the corrosion from the water inside light assembly.


    [​IMG]
    To start, remove the 4 screws from the corners of the cover and remove the cover.

    [​IMG]
    The ballast is mounted on the back side of the cover. Flip the cover over, and remove the black wiring connector (already removed in photo below). This connector supplies 12 volt power to the unit which is then converted to the 25,000 volts driving the HID lamps. Remove the 3 screws holding the ballast to the cover.

    [​IMG]
    To provide clearance for the connector removal the leveling motor must be removed. Turn leveling motor counter clockwise then disengage it from the housing then disconnect it from the reflector by turning the white aiming screw counterclockwise. (this picture was taken after I was finished so you can't see the connector, which would be in lower left of the picture or the wiring harness which would be passing through the opening at the right of the photo)

    [​IMG]
    The back, flat metal surface of the connector must be held tight to the flat surface of the plastic enclosure.

    [​IMG]Work it past the protrusion from leveling connector below. It is a tight fit but should not require excessive force

    [​IMG]Now past the leveling connector, we are looking through the ballast opening.

    [​IMG]Slide the connector to the right to the corner.

    [​IMG]Once in the corner there is clearance enough for removal

    [​IMG]And we are out!

    [​IMG]The HID lamp connector.

    My plan is to install a new ballast and reassemble everything and then seal the joint between the clear and black plastic halves with silicone sealant hoping this solves the water intrusion issue and prevents a re-occurrence.
     
    Raqune, Patrick Wong and Otter like this.
  2. bikr357

    bikr357 Plugged in Member

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    Ha so now I find the post on the HID warranty extension. Lucky me with 56K on an '09 and a ballast and headlight assembly seal issue but not a bulb issue I'm SOL.
     
  3. joer8278221

    joer8278221 Junior Member

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    Where did you get the ballast parts from and how much?
    I'm looking to do the same thing on mine because I also have condensation building up in my drivers side head light assembly and have just been replacing bulbs and dealing with the issue for far to long now.
    I am thinking of replacing the head light assembly too, because I think that O-ring that protect the bulb and ballast harness is the culprit for the moisture intrusion. Before I start anything I am trying to get an idea of total cost.
     
  4. ronjuan

    ronjuan Junior Member

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    Hi- I am having the same problem....the lens cover seal seems to have failed and am getting moisture in the lamp....dealer wants to replace the lens cover and says parts cost $475.00....crazy....what is the fix for this?
     
  5. Otter

    Otter Junior Member

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    I am in the process of fixing this leaking issue on my 2007 (the sealer is drying). Remove the headlamp assembly as noted in the video above. Unplug the lights (there is a little lock tab on each connector) rather than removing them leaving the bulb and the bulb socket in the fixture. Try to keep the clear portion facing the same way as it was situated in the car or facing up as you remove it and set it down. The reason for this is to keep any water inside the fixture from running down onto the lens where it is virtually unclean-able if it leaves any stains. The reason you want to keep the bulb holders in the assembly is to keep it sealed. At the very top and bottom of the assembly, you will see a odd shaped rubber cap with a filtered vent. Remove both of them. Then without shocking yourself, remove the HID power supply from the bottom of the fixture by removing the four screws and inspect it for wetness. This is where excessive water will settle in the assembly. The metal portion can also be removed from the plastic portion by removing three screws. Dry everything out in and around the ballast. (both mechanically and in the sun for a couple hours) When you are satisfied that the ballast is dry, reinstall it (or if you satisfied the ballast is fried, replace it). Now choose either hole where you removed the rubber cap and inject some kind of low pressure dry air supply. The location of the two holes makes the air run all the way through the fixture. My buddy's CPAP machine worked great. Run the dry air through the fixture to fully dry it out. While that is going on, take your finger and plug up the hole opposite the air supply (so it builds up mild pressure inside) and spray windex around the lens seal where the clear meets the black portion of the assembly. You will see bubbles where the seal is bad. Identify the location and then remove your finger from the hole so the fixture can continue drying out. Clean the leaky location using a 409 followed by rubbing alcohol and seal with a good RTV (Silicone sealer). When you think the fixture is fully dried out, replace the top and bottom plugs and reinstall the fixture. I changed out my turn and side marker bulbs while this thing was all opened up just to save grief later. My leak was on the drivers side fixture, and near the amber reflector portion of the assembly. Thanks to the original poster for this thread and also to Luscious Garage for posting a real time saving video. OTTER
     
  6. cmw1275

    cmw1275 Junior Member

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    Where did you purchase the replacement ballast? A YouTube mentioned hidconcepts.com however that domain is for sale.

    I replaced the driver's side headlight on my 2008 last year or the year before, it probably had at least 60K miles at that point. Last week, the passenger side went out (144k miles). After ordering a replacement bulb from Amazon I found it is not the bulb but probably the ballast. I commented to my husband last night about the condensation I noticed and just put two and two together after reading your posts.

    I previously found this thread about installing an HID relay harness to improve the ballast functionality and thought I would share: Prius Gen II HID headlight Question | Page 2 | PriusChat
     
  7. cmw1275

    cmw1275 Junior Member

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    My husband and I (mostly my husband) successfully replaced the passenger side ballast yesterday morning. It took about 2 hours I think. We did not install the relay harness I mentioned in the post above. I purchased the ballast from the HID Concept store on ebay. I believe they previously had their own website but it is no longer available. They had three ballasts with varying degrees of newness and warranty ranging from $93 - $150. I purchased the middle option for $120. They were also selling two ballasts and 2 HID lights for $260, a pretty good deal. If it wasn't the ballast our next plan was to find an entire headlight assembly at a salvage yard but luckily we didn't have to go that route. This information was especially helpful as well: Toyota Prius: How to Replace the HID Ballast/Computer/ECU - PriusDIY.com
     
  8. numba41

    numba41 Junior Member

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  9. Raqune

    Raqune Junior Member

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    Still Had to Remove Plug on 2005...

    Loved your awsome post bikr357, Very nicely documented! It is exactly the way I like to approach things - a little "inside the box" manuvering to avoid disassembling the new lamp connector and risk damage.

    Oddly this did not work on my 2005 Prius, odd because I assume you were working on your 2006 and I thought 2005-2006 headlights were the same. The 7th picture down showing the ribbed bottom of inner reflector - mine was smooth so there must have been a design change. I tried for over an hour to work the connector past the black clip that the automatic leveler screws into and there was no way to get it past without breaking something - if nothing else, I am persistant. The inside path past the screw clip you show was not even close for me, I could almost get it past going to the outside (between screw clip and black outer housing). I even tried forcing the reflector down and lifting on the black outer housing to provide a smige more clearance. In the end I had to disassemble the hi-voltage plug, if done carefully it would be hard to tell it was ever apart. The rest was pretty straightforward as documented in many other P-C threads.
     
  10. bikr357

    bikr357 Plugged in Member

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    Been off-line for quite sometime so I've only now seen your post. The repair was done on my wife's '09. The ballast was purchased used from an eBay vendor (I don't recall the name). The repair is still going strong two and a half years later with no reoccurance of condensation.
     
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