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Headlight Issues

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Michael Bones, Dec 31, 2021.

  1. Michael Bones

    Michael Bones Junior Member

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    Hello folks,

    So I have this issue. A few months ago I decided to renew my front headlight lenses on my 2007 because they just looked like crap. The process went well and they look almost new. Typical 3 stage sanding and then a buff out with plastic polish followed up by a clear coat meant for plastics. Now this is when things take a weird turn.
    After I took the car to the car wash I noticed a small amount of water condensation in both headlights. Now after a good rain storm I have a ton of water condensation in both headlights and to make it even worse...The left high and low beams just stopped working. When I raise the hood I can't seem to find any possible entry point for water to get into the sealed units. I've already looked at the vids on headlight removal and I've got the proper tools to do the job but I was wondering If anybody has addressed this problem before. All I can think of is that when I polished the lenses somehow I broke a seal on the units but when I look at them they seem to be fine. The leakage/condensation has been minimal recently and only happens after the drive through car wash. It has been drying out within a few days but now the issue got real bad after a week of rain storms. Obviously I need to get the condensation out of both units. Not sure if the bulbs in the left unit are shot now but I have to start somewhere. Side marker and turn signals work on both units but both high and low beams on the left unit just went out yesterday. Has anybody had such leakage problems before? Mine just leaked real bad with my car just sitting in the driveway for two days.
    Any suggestions on how to approach this issue would be appreciated. I will spend the money on the new bulbs which looks like about 40 bucks per pack of two which will be around 80 to do the job right but obviously I need to make sure they do not leak again. Look at the two attached pics. The driver side has more condensation which extends down into the area where the hid bulbs are. That is the side that has stopped working.

    Any input please,

    Mike
     

    Attached Files:

  2. Tombukt2

    Tombukt2 Senior Member

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    You're Hid or halogen . Either way I bought some decent aftermarket housings for $40 a piece that do not leak and are brand new plastic whatever that's worth My 0709 type setup the headlights are real good I have cleaned those before and I'm going to do them again they're in pretty good shape The ones I bought for $40 I put on an '05 to get rid of the HID and go to LED

    SM-A715F ?
     
  3. Michael Bones

    Michael Bones Junior Member

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    I also wanted to say that when I raise the hood there is absolutely zero moisture around the back of the headlight assembly. That whole area is protected by the hood. I inspected the areas where the clear lenses meet the black plastic and it looks perfect. For the life of me I can't seem to figure out where the leaks are.
     
  4. PriusCamper

    PriusCamper Senior Member

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    Both of them at the same time? This is really weird. That's a lot of water! And the covers where lights install are dry and still sealed? Did you use any power tools when you polished, or just hand polishing?
     
  5. Michael Bones

    Michael Bones Junior Member

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    Yes I in fact used a drill with a buffing wheel attached on both of them. Used a moderate amount of pressure to finalize the polishing. Now I am assuming that I created my own problem by fracturing the factory seal between the black back plastic and the clear lens. There are three micro screws that attach both pieces and I can clearly see some kind of sealant in between the two pieces. Not silicone but rather a foam based sealant.
    Back to the issue at hand....
    I removed the headlight assembly with the help of a youtube video. Not really that labor intensive. One 10mm socket setup. A philips head and slotted screwdriver and about 10 min. Disconnecting the various connectors was a little pain in the butt but I accomplished it without breaking any tabs so that was a plus. Now..... The one double wire (red/wht) that leads to what I believe is some kind of ballast for the lights was soaking wet (see pics). It is long enough to lay in the bottom of the whole assembly so I think the water wicked its way up to the connector. The connector clearly had a decent amount of water in it. I have the whole assembly on my kitchen counter with a small space heater blowing warm air into the assembly (see attached) we shall see the outcome of this adventure when everything is dry...LOL
    Hopefully it is just a wet connection issue rather than destroyed components/bulbs. No rain for this week so my timing is good at least.
    Once I resolve this issue I will use a silicon bead around the area that I think is leaking. The groove looks like it will accept a decent amount to seal it back up.

    stay tuned.........
     

    Attached Files:

    #5 Michael Bones, Dec 31, 2021
    Last edited: Dec 31, 2021
  6. Michael Bones

    Michael Bones Junior Member

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    Update.....

    After the drying out ... everything is good to go. Used a little dielectric grease on the connections, Plugged the assembly connectors all back in and everything lights up just fine. Applied a thin bead of black silicone around the entire seam that is suspected of leaking and now I'm good to go on doing the same procedure on the passenger side tomorrow.
    Moral of the story is ....after the headlight lens restore project I should have applied the silicone bead. Honestly I never even thought the pressure of the buffing wheel would have fractured the oem bead but it kinda makes sense since the car is 15 years old. Heck...If I had to do this all over again I'd probably order two aftermarket lens assemblies for $140.00 and install them.

    Take Care Everybody and Happy New Year....

    Mike
     
  7. PriusCamper

    PriusCamper Senior Member

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    Maybe test the headlight by going through the car wash again before you do the other headlight?
    It's still baffling to me... Those seals are really, really strong... So much so that if you want to paint under the clear plastic you have to bake the headlight in the oven to get it hot enough to separate that seam. Can't imagine how you could get that much water in there simply by polishing the headlight lens?
     
  8. Another

    Another Senior Member

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    What exactly was the "clear coat meant for plastics." that you used?
     
  9. PriusCamper

    PriusCamper Senior Member

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    It ensures that the freshly polished plastic doesn't get foggy again for a long time. For example I use a polish-wax on my car often and can make the headlight lenses look decent again just by doing that. But if you add a layer of clear coat the won't fog up again for many years instead of months.
     
  10. Another

    Another Senior Member

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    I understood the objectives, but wondered what exactly he used. It could have had a solvent in it that degraded the seal.
     
    PriusCamper likes this.