Headlight moisture and intermittent light failure

[willydoit]

Hi all,

our 2006 SC430 facelift model has moisture in the nearside headlight and just recently the headlight is failing intermittently, with an MOT due before putting it back on the road I need to resolve the issue.  The obvious solution to the moisture would be to replace the nearside headlight unit but finding one in the UK isnt easy so it looks like I will need to remove it, source the leak, repair and replace, not ideal but seems the only solution so any advice on that would be welcome. If anyone has a n/side headlight unit for sale please let me know.

The second issue is the intermittent failure of that units headlight, not sure if it is connected to the moisture issue, moisture is just moisture, there isnt any puddles of water in the headlight.  Not sure if this is likely to be simply a bulb issue or a ballast issue so again any advice on likelihood of culprit would be appreciated.

If I am going to have to remove bumpers etc I may as well replace the bulbs anyway but would welcome advice on what bulbs UK users have replaced theirs with as there seems to be a plethora of options and like others have said, I don't want to make a mistake and end up with having to replace them again in the near future.

If I am having to replace the bulbs I would like to achieve an upgrade in performance if possible and would welcome feedback from those who have changed their bulbs, their experience and the bulbs used.

I am not a mechanic and it has been many years since I got my hands dirty but resent the sort of charges a dealer would make just for changing headlight bulbs so again any/all advice is welcome.

Thanks in advance for any help provided.

[cruisermark]

Hi

I clicked on your post because a BMW we have in the family has exactly the same problem - we have had the headlight our countless times, dried, pressurised it and sealed it but the problem still persists - we are now looking either sourcing a new (singing and dancing LED adaptive) light a a cost of over £100 from the dealer or risk it with a second hand unit. Funny thing is we have even replaced the caps at the back with new ones but water still finds its way in.

Anyway back to topic: thankfully Lexus lights are very reliable - the only time I got moisture in mine was when one of the rear caps on the headlight came loose and dropped off in the back - that would be my first point of call.

If all looks good then you will have to remove it and check all the apertures for any broken or perished seals.

[willydoit]

Hi, thanks for that, I will check the caps before delving into removal and testing for leaks, unfortunately a new sc headlight seems to be around £600 so need to try all possible alternatives before going that route 🙂

[Malc]

In olden times a simple trick was to gently loosen off / remove the weather sealing / grommit part at the bulb insert area and turn on the lights to generate heat to dry it all out, then pop the grommit / sealing part back ..............  perhaps even leave it fairly non-air tight anyway to enable any moisture to never build-up !

But that was with olden style cars where headlights were generally of a simplistic design and style and headlight bulbs actually generated a little heat too

It was all so simple, perhaps it hasn't really changed ?

Give that a try maybe and see how it all goes ....  and it's free of cost too if you can get to do that yourself maybe 

Malc

[willydoit]

Thanks Malc, I will have a look at it all tomorrow, just got back from my covid jab so that's my lot for today 🙂 from what I have seen, HID bulbs produce more heat than halogens so that may well do the trick, fingers crossed.

[ALAW]

Hi Steve

This has been a problem manufacturers have battled with for years not so much now with the advent of LED lights which give off very little heat if any at all. In your case i think Malc has the answer. What i will add is can you see a vent anywhere is it blocked. Good luck.  

[willydoit]

Hi all, sorry for the delay in getting back, covid jab knocked me off my feet for a couple of days. I have removed the headlight and there was far more water in there than I realised, most of which would appear to have been sat in the ballast housing 😞 I cannot see any obvious areas where the water could have got in yet though.

Anyway am replacing the ballast hopefully today if it arrives in time and I am also replacing the two hid bulbs.  Just a note to be aware of for others looking to replace these bulbs.  I purchased two Osram cool blue DS2 from amazon which according to the listing and the Amazon garage element were the correct ones for my vehicle, after fitting the lights would turn off after a few seconds.  Turns out they are not the right ones, the correct ones on mine are DS4 so I know it causes delays but if changing yours I would suggest removing and checking the version from the old bulb before ordering a replacement.

Not sure how easy it will be to replace the ballast in respect of routing the cable inside the headlight so any experienced help there would be appreciated.

Thanks all who offered advice