broken fog light, help.....

[whatever]

One of my fog light is cracked and the other one, well, the glass was shattered. I'm not sure how it happened. Anyways, I been driving around with them like for almost a month and finally decided to replace them. Now, when I go turn on the fog light, it doesn't come on at all. I checked the fuse and it looked like it is still ok. Anyone experienced this? Any ideas?

[caball]

yeah i had the something like this happen when i replaced the lamps. the ground wire wasn't connected right. u could check that but it probably is something else. also did u replace the fuse with another to make sure it was alright?

[AlEkZ]

when you say the fuse do you mean the bulb?? or the actual fuse...anyway, check the bulb, try the bulb that works on the fog that isn't working to check if its the fog or bulb...make sure you're getting it connected right....BTW about a week after I replaced my fogs they broke again...and I've had them like that for like 6 months now...I hope you have better luck with yours!:

[whatever]

Was thinking about that. I think I will go try the fuse tomorrow just to make sure. It seems like a cheap enought to try even if it's not the fix...

[Sean~328i//EastBay]

whatever,
laster i heard the fogs crack not always because of chips on the road but more due to the heat generated within and then something like water hits and cracks it up. so after you get some new ones, you can try this. Take some alumunium mesh and cut it to fit over the fogs tightly such that the mesh touches the fog lens. it will also fit back into the fog housing perfectly. i know this because i have done so myself.
anyway the reason for this is that the alumunium mesh will protect your fog lens in 2 ways. Firstly simply as a metal barrier, secondly and more importantly it acts as heat sink s.t the heat generated by the fog lens is immediately dissipated into the atmosphere. Remember for this your mesh must touch or be in contact with the fog lens.
Reason for lens breakage is because the co-efficient of expansion of glass is lower than metals (glass is a bad conductor of heat), thus the inner part of the lens heat up and starts to expand while the conduction of the heat generated does not transfer fast to the outer part of the lens. As a result the expansion of glass on the inner and outer side is unequal and when it comes in contact with water or a drastic reduction in temperature it breaks.The mesh prevents this and allows even heat dissipation.
This low co-efficient of expansion of glass also explains why sometimes moonroofs or windows explode during severe winter.