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Frosted glass headlamps
Posted: Fri Aug 15, 2025 1:57 pm
by Michiel
I bought a new pair of halogen headlamp units and bulbs from a reputable UK supplier. After only a few hours with the lights on (lowbeam) the glass is now dull, frosted inside. It looks like it's the glass, not the reflectors. I did not touch the bulbs with my fingers. Any ideas as to the cause?
Re: Frosted glass headlamps
Posted: Fri Aug 15, 2025 2:19 pm
by Bill_qaz
Best guess. Possibly some sort of preservation coating on glass that reacted to the heat assuming its not just moisture inside.
Can you post a picture?
Re: Frosted glass headlamps
Posted: Fri Aug 15, 2025 3:31 pm
by Michiel
It is not moisture.
Re: Frosted glass headlamps
Posted: Fri Aug 15, 2025 5:02 pm
by svenedin
Are the headlight units actually glass or are they plastic or partially plastic? It sounds to me like something has overheated or smoked causing a deposit on the back of the front lens. Is there any sign of burning, scorching or melting? I would take your issue up with the supplier. Some plastics are damaged by the UV emitted by Halogen bulbs but this usually takes a long time. Are you sure there is no protective film on the glass that should have been removed?
There are good quality, all glass, halogen headlight units sold under the Lucas brand but the best as far as I am aware are made by Wipac in England.
Stephen
Re: Frosted glass headlamps
Posted: Fri Aug 15, 2025 6:07 pm
by geoberni
Just to reiterate Bill's request, please post a photo, if it shows up on a photo.
I found that the Halogen Lamp Units fitted to my car had a faint blue 'bloom' to the glass; an almost smoke like contamination.
They are Wipac Units.
When I replaced the rear bowls last summer, I cleaned it all out using a soft cloth put in through the Bulb Mounting hole and rubbed around the glass with a long screwdriver. It hasn't come back (well, not that I've noticed
)....
Spot the difference:
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- 20240114_125155.jpg (1.29 MiB) Viewed 56110 times
- 20240114_125311.jpg (1.85 MiB) Viewed 56110 times
I first noticed it when I fitted LED lamps to replace the Halogen Bulbs (back in 2019), but I didn't do anything about it at the time. When I replaced the Bowls, I thought I'd try cleaning them out.
Re: Frosted glass headlamps
Posted: Fri Aug 15, 2025 6:39 pm
by svenedin
geoberni wrote: ↑Fri Aug 15, 2025 6:07 pm
Just to reiterate Bill's request, please post a photo, if it shows up on a photo.
I found that the Halogen Lamp Units fitted to my car had a faint blue 'bloom' to the glass; an almost smoke like contamination.
They are Wipac Units.
When I replaced the rear bowls last summer, I cleaned it all out using a soft cloth put in through the Bulb Mounting hole and rubbed around the glass with a long screwdriver. It hasn't come back (well, not that I've noticed
)....
Spot the difference:
.
20240114_125253.jpg
.20240114_125155.jpg20240114_125311.jpg
I first noticed it when I fitted LED lamps to replace the Halogen Bulbs (back in 2019), but I didn't do anything about it at the time. When I replaced the Bowls, I thought I'd try cleaning them out.
Interesting. I have the same Wipac units Berni. I will check. I didn't notice anything just now whilst I was preparing the Morris for a car show tomorrow (Capel).
Stephen
Re: Frosted glass headlamps
Posted: Fri Aug 15, 2025 10:05 pm
by Michiel
Sorry, no photos. I'm on holyday and left my MM at home. I know, stupid. But the reflectors are Wipac and the fogging of the glass is far worse than on Geoberni's photos. A clue could be the material of the led non-standard pilot lamps. Yes, something must produce some smoke. Have to see where that comes from before buying new ones. Or clean up the existing ones. Has anyone succeeded in separating the glass from the reflector ?
Re: Frosted glass headlamps
Posted: Sat Aug 16, 2025 9:41 am
by geoberni
Michiel wrote: ↑Fri Aug 15, 2025 10:05 pm
Has anyone succeeded in separating the glass from the reflector ?
I wouldn't risk it.
Even if you got it apart without damage, reassembly and getting the alignment correct would be an issue, plus what adhesive to use. Just too much hassle and risk IMHO.
The hole on the back is plenty big enough, even working around the shielding that's in there to get the beam pattern.
Re: Frosted glass headlamps
Posted: Sat Aug 16, 2025 12:08 pm
by svenedin
I looked at mine which are Wipac with halogen bulbs. I can see no evidence of internal frosting/haze
Stephen
- IMG_2415.jpeg (2.38 MiB) Viewed 56027 times
Re: Frosted glass headlamps
Posted: Sat Aug 16, 2025 1:21 pm
by Michiel
Must be the bulbs or pilotlamps I have then.
Re: Frosted glass headlamps
Posted: Sat Aug 16, 2025 2:30 pm
by svenedin
Michiel wrote: ↑Sat Aug 16, 2025 1:21 pm
Must be the bulbs or pilotlamps I have then.
Just for info, mine do not have pilot lamps.
Stephen
Re: Frosted glass headlamps
Posted: Sat Aug 16, 2025 2:35 pm
by Michiel
OK, thank you all for the replies.
Re: Frosted glass headlamps
Posted: Sat Aug 16, 2025 3:49 pm
by Bill_qaz
Also wipac with pilot lights installed, looked at recent picture and can't see anything on glass even when zoomed in.