Frosted glass headlamps
Forum rules
By using this site, you agree to our rules. Please see: Terms of Use
By using this site, you agree to our rules. Please see: Terms of Use
Frosted glass headlamps
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?
Finished rescuing a 1967 2-door. Define finished....
- Bill_qaz
- Minor Legend
- Posts: 2279
- Joined: Fri Jan 14, 2022 7:31 pm
- Location: Oxfordshire
- MMOC Member: Yes
Re: Frosted glass headlamps
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?
Can you post a picture?
Regards Bill
Re: Frosted glass headlamps
It is not moisture.
Finished rescuing a 1967 2-door. Define finished....
- svenedin
- Minor Legend
- Posts: 4798
- Joined: Fri Aug 29, 2014 9:27 am
- Location: Surrey
- MMOC Member: Yes
Re: Frosted glass headlamps
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
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
1969 1098cc Convertible “Xavier” which I have owned since 1989.
Stephen
Stephen
- geoberni
- Minor Maniac
- Posts: 5246
- Joined: Fri Aug 04, 2017 11:19 am
- Location: North Leicestershire
- MMOC Member: Yes
Re: Frosted glass headlamps
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:
. . 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.
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:
. . 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.
Basil the 1955 series II


- svenedin
- Minor Legend
- Posts: 4798
- Joined: Fri Aug 29, 2014 9:27 am
- Location: Surrey
- MMOC Member: Yes
Re: Frosted glass headlamps
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).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.
Stephen
1969 1098cc Convertible “Xavier” which I have owned since 1989.
Stephen
Stephen
Re: Frosted glass headlamps
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 ? 
Finished rescuing a 1967 2-door. Define finished....
- geoberni
- Minor Maniac
- Posts: 5246
- Joined: Fri Aug 04, 2017 11:19 am
- Location: North Leicestershire
- MMOC Member: Yes
Re: Frosted glass headlamps
I wouldn't risk it.
The hole on the back is plenty big enough, even working around the shielding that's in there to get the beam pattern.
Basil the 1955 series II


- svenedin
- Minor Legend
- Posts: 4798
- Joined: Fri Aug 29, 2014 9:27 am
- Location: Surrey
- MMOC Member: Yes
Re: Frosted glass headlamps
I looked at mine which are Wipac with halogen bulbs. I can see no evidence of internal frosting/haze
Stephen
Stephen
1969 1098cc Convertible “Xavier” which I have owned since 1989.
Stephen
Stephen
Re: Frosted glass headlamps
Must be the bulbs or pilotlamps I have then.
Finished rescuing a 1967 2-door. Define finished....
- svenedin
- Minor Legend
- Posts: 4798
- Joined: Fri Aug 29, 2014 9:27 am
- Location: Surrey
- MMOC Member: Yes
Re: Frosted glass headlamps
Just for info, mine do not have pilot lamps.
Stephen
1969 1098cc Convertible “Xavier” which I have owned since 1989.
Stephen
Stephen
Re: Frosted glass headlamps
OK, thank you all for the replies.
Finished rescuing a 1967 2-door. Define finished....
- Bill_qaz
- Minor Legend
- Posts: 2279
- Joined: Fri Jan 14, 2022 7:31 pm
- Location: Oxfordshire
- MMOC Member: Yes
Re: Frosted glass headlamps
Also wipac with pilot lights installed, looked at recent picture and can't see anything on glass even when zoomed in.
Regards Bill