Well, my first post and I'm not contributing, just leeching, I'll make up for it it once I pick up my SC 400 tomorrow.

Here's my question:
After checking out about 10 different SC400's, I've noticed a few that have condensation in the headlamps. Is this a typical problem with SC's? Someone told me that the headlamps are so tightly sealed due to the aerodynamics of the car, that there's no air exchange and so the condensation comes in. Sounded like a load of bull to me...
Incidentally, the proposed solution was to drill small holes under the headlamps. Any comments?

 

There's lots here on the subject, use the search box - -

 

Do a search.... search for headlight and you will find your answers.... several in fact..

DO NOT drill a hole in the lens....

In fact there are a couple drain plugs in the rear of the lens already.

You need to pop the lens off and clean it...then reseal it so the moisture doesnt get back in from the top of the headlight due to rain or washing.

 

PCMW, Byrner was asking about drilling holes into the 'black' headlight casing from underneath and not into the lense itself.

So although I understand (and agree with) your advice about not drilling into the lense....... does that still hold true for drilling into the casing?

Taking the headlight unit apart for cleaning and then resealing it does cure the condensation problem but not permanently. The majority of units that I have seen that have been opened for cleaning get the condensation problem back eventually, anything from a few months to a couple of years.

The 'drain plugs' already on the headlight unit do not cope with condensation on a headlight that has a 'faulty' seal. Otherwise we wouldn't see so many headlights with this problem on SC's and Soarers.

Drilling two extra holes in the underneath of the headlight casing does help with condensation, though if you can find a valve or two to insert into the new holes to stop water gaining access you'll have a better solution.

 

Interesting theory....but here is my view of it...

1. Why drill a hole when there are already two holes drilled in it? What would two more do for you?

2. If you drill thru the bottom of the light you will hit the silver/plastic/metal. The bottom of the light is actually against a silver plastic reflector with a metal chrome attachment. Drilling into this will wreck the reflector causing it to CRACK.

3. If water is still getting in after the re-sealing of the lens then it was done hastily and not truly sealed. I say this because I have a 10 year old light on my car with NO condensation.... big difference is that the caulking is much heavier on that one. I traced the major leak to the top area near the mounting screw where water tends to SIT and slowly drip in over time. If you fill this entire area with sealant then the problem goes away. Much like the theory of a rain gutter carrying the moisture away preventing the trapping of the water into a puddle.

my .02

 

DO NOT DRILL A HOLE IN ANYTHING. Drilling holes can only worsen the problem. You have condensation because of a crack somewhere on the housing. Located it and seal it with silicone sealant. The problem will be solved if all breaches on the housing are sealed. As for the water stains on the lens cover, you have to open up the headlight housing to clean it.

 

I'd be interested in the findings of those who have actually taken the headlight apart...... for cleaning and resealing.

The success rates, any problems, how long before condensation came back if at all, how long its been since you fixed the problem.

To 'pcmw', sounds like you have done the perfect repair, I like the addition of the 'rain gutter', that may be the missing link/repair for everyone who has had the problem. By the way, when the unit is seperated you can drill holes..... If the two vent holes were sufficient to cope with condensation then our headlights would never suffer from this problem....... I would be interested in finding out how long it has been since you performed the repair?

One of the issues I have found in repairing the headlight is that during the 'heating' process, when you pull the lense from the housing the softened sealant pulls apart, as this then rehardens it creates an uneven surface at the bottom of the trough that the two parts join together in. Irrespective of how much sealant you then add to the joint when putting the two pieces back together you always have a less than air tight surface. As a 'human' you cant but help put different amounts of pressure on the housing as you squeeze the two back together. This creates even more irregularities, as soon as one of these fails due to the pressures the headlight is subjected to, condensation comes back. Still thats my experience.

 

I read something on the UK Lexus Soarer site about how water gets into the headlight modules (apparently it rains in England) - somebody mentioned the front fender liners - they said make sure that all the fasteners and plugs are in place in the front portion of the liners or the rotating front wheels will throw moisture through the holes onto the back and bottom of the module - and the water may actually get *in* through the drain holes! Bottom line: make sure the fender liners are intact, properly fastened, and sealed up! FWIW....

 

BTW, my SC4 is a '93, in Seattle (it rains here too) since new but always garaged, and the headlights have no sign of condensation.

 

Also, would there be a way to place a packet of silica gel desiccant somewhere in the housing to absorb ambient moisture? Just a thought - you know, the little packets that come packed with new products that are marked "Do Not Eat" -

On that subject, and on the infamous "Objects are closer than they appear" etched into the passenger side mirror - do you suppose some day the Gov't will require screwdriver manufacturers to label their products with "Do not insert pointy end in eye" or scissors makers to label their product "Do not run while holding this product" ??

 

'S'Low Rider


I went with the 'Do it right and do it only once' theory of headlight repair.
Step 1. Heat at 175F
Step 2. Use paint scrapper and putty knife around the entire lens. I just slid the knife along the lens to peel back the glue.
Step 3. Re-Heat
Step 4. Begin separating the two sides working from the bottom first in order to insure that I didn't bend the top black plastic that is so important.
Step 5. Separate the two sides.
Step 6. Clean out ALL old sealant from both sides. (1hour+)
Step 7. Fill black backing side of headlight component with RTV Sealant.
Step 8 Insert the lens into the fitting.
Step 9. Heat at 175 for about 10 mins
Step 10. Let dry and re-clip the metal tabs.
Step 11. use extra RTV Sealant to fool-proof the top side of the headlight by creating an excess of sealant and therefore moving the water away from the gap.

 

pcmw, are you actively heating the headlight at 175? What I mean is is the oven on while the headlight is inside, or did you preheat it and shut it off then insert the headlight?? Thanks...

 

Hey what's up
Just wanted to tell you guys what I have done to get my dam lights clean. and maybe it will help you!

1st of all DO NOT DRILL HOLES in anything I can't say this enough that will only mess it up even more.
2nd be careful with the whole oven thing because I tried it on an old light I had layin around and I melted the housing. So be careful with that.
3rd I just take the head light off and pour a liquid ie: alchol, scope (yea the mouth wash) anythin that has a think consistency and won't leave water spots in the lense. And then swirl it all around until u get everything clean then pour it out. Then get a blow dryer, and take out all the bulbs and from the hole where the turn signal goes in put the blow dryer and just let the warm air circulate in there, and in 10-20 min you will have a clean water free lens.
Then last but not least seal it with the best sealant u can find, and your main concern should be on the top portions especially where I think water might collect. You might need a coupla coats to seal everything, put its worth the time because if u spend some time now when you’re lights will stay clean and not get yellow.
And you’re done, if u do all these steps right you will hopefully have a clean, clear, dry light permanently.

 

I drilled 6 little tiny holes 6 months ago in the headlight clear plastic. It cured the water problem and I have had no ill effects. What is it that you think is going to happen with the holes and or headlight?? BTW the drilling of holes was presented here as "the" solution about a year ago!

 

Ok may be it worked for you but one of my friends drilled some holes in his lights clear plastic and it really didn’t help at all, and it made the lights get even dirtier. So my opinion is don’t drill holes just try to clean and seal it.