S-Prihadi

Jet,

Your headlight in that photo a 640 dynamic LED ?
Those desiccant wont last very very long, you have to renew them. Can you actually access Left headlight desiccant CAP with so much components there ?

I can't access my left HL now that I have insulated refrigerant line from condenser to Internal Heat Exchanger.
Its never a good access anyway with washer fluid bottle and ABS/ESP pump and fuel vapor injection.





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S-Prihadi

Continue............

The dry air injection is a success. I use dry nitrogen instead, because I have the proper regulator for it to set to very low pressure.
My scuba air is minimum 130 PSI, so too high and its difficult to regulate the air pistol for slow low pressure flow.


Temporary set up for testing only.
The white bulkhead fitting is actually for Reverse Osmosis water fitting. The tube with pink color is a check valve. So I use it as STOP VALVE.
It is not glued permanent yet, I am still using simple double side tape, magic nano type, not 3M.



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Run the headlight to 40+ Celsius temperature. Engine is OFF.
Right side headlight is the dry nitrogen injected one, the left headlight is still as-is, stock.





Freeze Spray ( R134A refrigerant ) to create temperature difference at clear lens oustide surface and then the coldness will migrate to the inner lens and will be hit by moist air inside the headlight and fogging will occur.






LEFT headlight will fog, because the air inside it is already no more dry as back when new in 2014.
RIGHT headlight has dry nitrogen inside it. So it wont fog or very difficult to fog .



Mercedes is not bulshi-tting about plastic will transfer moisture. That is true.
I deal with dive compressor dry air down to -70C dew point dry when filter media is new and retire the media by -42C dewpoint. This is 0.00x % kind of humidity...crazy dry.
Storing good 13X desiccant which we call Molecular Sieve, you must use metal container. Plastic will migrate water moisture from outside in gas form to the inside of the container.

Any proper crispy food will use thin aluminum foil as packaging and is nitrogen filled. This will last very long.
Crispy food in my country if home made uses regular plastic, maximum 1.5 week and the crispy is gone.
Water moisture is much smaller than liquid water , it goes thru plastic.

If you have a pool light with replaceable halogen bulb , it will have o-ring. Chlorine gas will migrate thru the o-ring and cause corrosion, I kid you not.
Pool has typical 2.0 PPM fo chlorine at all times to sanitize it.


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If this glue holds well when dried for 24 hours, I will do the same for Left headlight.
The headlight is PP plastic and the white RO fitting seems like nylon. This 2 types of plastic is very difficult to glue.
The Loctite 495 is basically Crazy Glue.

Loctite 495 is a low viscosity, transparent ethyl cyanoacrylate adhesive. It is a general purpose adhesive, suited for a wide range of materials.
Loctite 495 is effective on hard-to-bond surfaces, like plastic, metal and rubber.

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LEFT headlight fogging. In photo form.




Will update more about the glue-ing in a day or two.

S-Prihadi

Something sad about my headlights, BOTH of them.
Whoever assemble the headlights , did not spare me 3cm extra wire free-play for CONTROL UNIT module, the big one.
I can't even get my fingers to try to disconnect the two connectors. The big connector is the one so very short wire assy.
How the hell if one day the CONTROL UNIT goes bad ( I pray it wont ) and I can't even remove it ?





The smaller module, ACTUATION MODULE has long enough wire free-play. I can remove it easy.



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The CONTROL UNIT module highest pull out is as below : DAMN !!!!!




See. the wires bunch is already maximum pull out, no more spare free-play.


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I think they installed this modules first, and then install all the LED-s array, and then sealed the headlight.


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I wonder what this small round knob does ? It can spin using 5mm allan key, but it wont come loose. The WIS does not say anything.
It is not beam height adjustment.






This grey rectangular piece is like rubbery material. Is this a membrane of some sort ?



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There are 3 foam type seals on my 641 headlight.
2 for the metal MODULES and 1 is for the connector.




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I think these small metals are where they radio weld the headlight. There are many of this metal thingy. Alignment pin maybe ?


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All these screws seems to be penetrating type, outside to inside, the ones in RED. It must be securing something inside the headlight.
The green ones seems to be from INSIDE to OUTSIDE.
These can cause micro air leak long term.

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The sealing of this headlight is not gas tight class kind of sealing.
Its a matter of time when eventually the air inside it will be contaminated by wet moist air when the situation is right.
Hot humid day and then suddenly raining cold yada yada.

So the desiccant pack cure is a must in the long term.
If I use desiccant pack, get one with color change capable, that way you guys can see when it is already moisture laden.
https://www.silicagel.com.au/silica-...nk-3-5mm-beads

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I was tempted to vacuum dry my headlight internal with my HVAC vacuum pump.
But I am afraid at -14PSI negative pressure, the headlight might implode inwards or may crack at the welding region.

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JettaRed

iTrader: (1)

No, I just have the boring Bi-Xenon Headlights with Active Curvelight. I can access the rear cap easily. I've had the desiccant in there over a year and no fogging. It probably needs replacement, but I'll wait.

JettaRed

iTrader: (1)

@S-Prihadi do you tie-wrap this to the bumper? I don't know how you would fit it in the engine compartment.

S-Prihadi

Dang, why didn't I think of that

JettaRed

iTrader: (1)

Well, I was trained as an engineer, and an engineer's job is to solve problems.

S-Prihadi

The glue held well, at least for now. I hope this will last at least 2+ years.
For RIGHT side headlight where it is easy to access nitrogen injection when needed, I decided to use a plug instead of hose and check valve.




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I ran out of the small bottle freeze spray.
So I used recovered R134A, which probably is like 3 pounds I have.





All good, no fogging.





These values are LED modules temperature, I think for ambient air temperature inside the headlight it will be say 2C cooler ?


ABOVE : Notice box 663, LEFT SIDE headlight at 41 Celsius, I actually removed it and I did get a DTC but see how the car module or Xentry likes to place substituted value for its temperature

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Look Ma, no LEFT headlight




See, even the RIGHT headlight module itself is declaring LEFT headlight is having a MAILFUNCTION ( missing ), yet it gave the temperature of LEFT headlight...LOL



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Next, me drill the LEFT headlight for nitrogen injection port.
I was spending hours yesterday and today cleaning what I can clean with bumper removed and some plastic frame of the condenser. I am spent.
I was also making improvement for chaffing protection on some of the wires.

Will continue in a few days.......

S-Prihadi

I forgot to add.
1 unit headlight power consumption is approx 4 amps. Approx 52 watts overall at 13V.

With 2 headlights and all modules running with ignition ON. 21 ish amps




Only RIGHT side headlamp, and all modules with Ignition ON.



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S-Prihadi

CORRECTION Stupid me

The round thingy with 5mm allan is the HEIGHT ADJUSTMENT...Dugghhhh



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The side adjustment is easy to ID from its white gear system.



The black cover is protection cover, so less prone to accidental adjustment.






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LEFT headlight.

The fan clearance is tight.








But the bulkhead fitting is a dual unit for two tubing to inter-connect, so I can cut it shorter and loose the inner side and keep the exterior side.





Glued today. Will wait 24 hours to let it dry. Tomorrow I can install.



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S-Prihadi

The 3 mounting screws for the headlight.
- Bumper removal - YES
- Wheel inner liner removal - YES, only the forward part. There are two parts inner liner. Rear and front.

The WIS , photo stingy document !! Applies to Facelift W212





I shall give you pictures rich easy to see version................


Number 1 screw if based on Mercedes WIS. See screw with red dot.





Number 2 if in WIS.



Yes, the screw is from underneath.




Number 3 if in WIS



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