Headlamps have moisture absorbing bags within them...

D

Dougal62

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This is a general question. I have recently replaced my halogens with LEDs. Nice white light without being over the top. Certainly can see the road clearer at night. Originals are quite pathetic really.
I noticed when changing the lights that the lamp head units contain bags of what I presume is silica gel for moisture absorption.
I think these bags might be contributing to dark shadows immediately in front of the car (well 3 to 5 metres ahead).
Is this normal for a 2021 first series ZS EV.
Thanks to anyone that can shed some light on the subject.
 
  1. Putting LED headlamps in halogen units is an MOT failure and possibly an offense as the light beam could dazzle oncoming traffic. If you are involved in a traffic incident the insurance company could refuse to cover you even if lights were nothing to do with the cause.
  2. I've never seen silica gel bags in a head lamp, they must have been left in by mistake. Once they have absorbed all the moisture they can handle they would just be a weighty mass to bounce around in the unit and damage the lamp.
 
Tweed98 said:
  1. Putting LED headlamps in halogen units is an MOT failure and possibly an offense as the light beam could dazzle oncoming traffic. If you are involved in a traffic incident the insurance company could refuse to cover you even if lights were nothing to do with the cause.
  2. I've never seen silica gel bags in a head lamp, they must have been left in by mistake. Once they have absorbed all the moisture they can handle they would just be a weighty mass to bounce around in the unit and damage the lamp.
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I totally agree with your comments and reasoning. It's a risk I'm willing to take for a lamp with similar shape of light on the road but brighter and in my humble opinion, safer. I did wonder about the logic in leaving the bags in the units and thought it was a mistake on the production line. They are big enough that they will not bounce around as they seem held in by the wiring but having worked in an electrical/electronic environment over the years I could not believe they are supposed to be there. It is my intention to remove them after taking photos. These bags themselves could potentially have caused an accident because of the restriction in illumination of the road at night. I wonder who may have been prosecuted then...
Thanks for your insight.
Oh, and after discussing the LED approval with my local MP, apparently we are just waiting for agreement with Europe on a standard. Several manufacturers are releasing lamps like the ones I have bought that 'should' confirm but, as you say could be a bone of contention if the cause of an accident. Having said that I doubt an argument against the LEDs would pass muster with the horrendous amount of badly fitted lamps and other illegally fitted high discharge lamps in cars already.
Thanks again.
 
IMG_20230227_094705_743.jpg

This is what I took out of my cars headlamp units today. Thanks MG. Your quality control continues to amaze...
 
Kithmo said:
Leave them in, they're there to absorb moisture and prevent the headlamp misting up inside.
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I've just spoken to dealer service and they agreed it was a mistake at production or something. Anyway, as another member has said, once the silica gel has become saturated there is no way to dry it out automatically and moisture would build up anyway. The headlight design is very very bad in this day and age if Silica gel has to be used as a stop gap to absorb moisture. At some point in the future the adhesive tape holding the bags in place will deteriorate and the bags will detach and roll around the unit. No I can't believe they are supposed to be there. It's dangerous.
 
Dougal62 said:
I've just spoken to dealer service and they agreed it was a mistake at production or something. Anyway, as another member has said, once the silica gel has become saturated there is no way to dry it out automatically and moisture would build up anyway. The headlight design is very very bad in this day and age if Silica gel has to be used as a stop gap to absorb moisture. At some point in the future the adhesive tape holding the bags in place will deteriorate and the bags will detach and roll around the unit. No I can't believe they are supposed to be there. It's dangerous.
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"Dangerous"? What's the worst case scenario here?
 
Bag gets stuck in from of lamp and blocks light when driving. Bag catches fire due to heat from lamp (don't know what the bag material is but feels like a woven plastic). Both of these scenarios could be potentially life threatening if they were to cause an accident.
There were certainly dark shadows cast and poor light from my headlights. I'll find out tonight if I get proper light thrown onto the road now.
 
Dougal62 said:
Bag gets stuck in from of lamp and blocks light when driving. Bag catches fire due to heat from lamp (don't know what the bag material is but feels like a woven plastic). Both of these scenarios could be potentially life threatening if they were to cause an accident.
There were certainly dark shadows cast and poor light from my headlights. I'll find out tonight if I get proper light thrown onto the road now.
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Shurely these bags are in the rear of the light housing? Otherwise you could see them from the outside? Which you can't....
 
You can't see them because they are behind the behind/underneath the lamps behind the projector lens. You can't see anything behind one of these lenses.
 
Dougal62 said:
You can't see them because they are behind the behind/underneath the lamps behind the projector lens. You can't see anything behind one of these lenses.
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So the only way they could get in front of the lens/lamp is if they somehow levitate? I'm not seeing the threat here 🤷🏻‍♂️

Has it happened on any vehicle?
 
The bags are big enough that they could 'theoretically' get in front of a lamp. You did ask for a worst case scenario. I have been a departmental safety advisor in my lifetime and having to look at all possibilities is something I have been trained to do. Do you/anyone else have these bags in the lamp units? I've seen no-one else mention them but they are obvious as they are so big.
Another thought is if these projector units use a moveable flap inside to manipulate the light from high to low beam (I don't know the design of these particular ones) then again, a detached bag could interfere with the mechanism.
 
Dougal62 said:
Oh, and after discussing the LED approval with my local MP, apparently we are just waiting for agreement with Europe on a standard. Several manufacturers are releasing lamps like the ones I have bought that 'should' confirm but, as you say could be a bone of contention if the cause of an accident. Having said that I doubt an argument against the LEDs would pass muster with the horrendous amount of badly fitted lamps and other illegally fitted high discharge lamps in cars already.
Thanks again.
Click to expand...

I agree, energy saving and added light would go a long way to improving the roads. Even properly fitted LED and HiD lamps dazzle on coming traffic.

I just think it should be a level playing field, you dazzle me, I dazzle you!:LOL:
 
Tweed98 said:
I agree, energy saving and added light would go a long way to improving the roads. Even properly fitted LED and HiD lamps dazzle on coming traffic.

I just think it should be a level playing field, you dazzle me, I dazzle you!:LOL:
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I believe one day we will all have implants or gene splicing to give our eyes the ability to see as well as cats do in the dark and we won't need bright lights shining the way ahead...
 
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Just found a video explaining the working of the projector headlamp and it would seem the bags I found are covering part of the reflector bowl that is needed for light output.
 
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The silica bags are behind the reflector, which is behind the flap mechanism, which is behind the projector lens, so they would have to squeeze past the reflector to start with, where there is no opening big enough for them to go through.
Zero risk IMO.
 
Dougal62 said:
The bags are big enough that they could 'theoretically' get in front of a lamp. You did ask for a worst case scenario. I have been a departmental safety advisor in my lifetime and having to look at all possibilities is something I have been trained to do. Do you/anyone else have these bags in the lamp units? I've seen no-one else mention them but they are obvious as they are so big.
Another thought is if these projector units use a moveable flap inside to manipulate the light from high to low beam (I don't know the design of these particular ones) then again, a detached bag could interfere with the mechanism.
Click to expand...
When I changed my bulbs they were in mine too
 
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