What causes lights to melt?

[PranK]

These are the tail lights from my E90. I have replaced the drivers side one previously so these two light housings come from 2 different cars.

What the hell is causing them to melt? The passenger side light lets so much light from the brake into the indicator it looks like its on! 

I'm assuming a manufacturing defect, but this plastic is super hard. It'd take some crazy temps to melt it.

 

[GTSBoy]

Wrong globes?

[PranK]

5 minutes ago, GTSBoy said:

Wrong globes?

Is that a thing? I can't imagine that most tail light bulbs would be that much different? I just bought all new bulbs and they are each 21w in the tail lights. 4 of them. Most of the  other bulb holes seem ok (but not all)

[GTSBoy]

21W is brake light, no? Tail lights are meant to be lower?

[PranK]

All the bulbs in the tail are the same. Checked them today. Can't believe the Germans didn't make a proprietary bulb for each use. Guess they missed a trick. 

[White GTS-T]

I'm with GTSBoy on this one. 12W are tail/parker globes and 21W are for brake light globes. A stop/tail globe will have dual filament 12/21W filaments. Just be sure to double check that you're not putting single filament globes where double filament globes are supposed to go and vice versa.

[PranK]

Yeah, def same power.

[GTSBoy]

No. Tail light globes are not 21W. You put 21W in burning ALL THE TIME (when the lights are on) and you will overheat the housing.

[Rusty Nuts]

15 hours ago, PranK said:

All the bulbs in the tail are the same

When I bought my E36, I noticed one taillight was much brighter. On inspection it had a 21W bulb in the tailight position which had melted a big hole in the inner reflector.

[PranK]

I don't know what to tel you guys, searching Autobarn, Narva, Ecstuning, Turner Motorspot, they all show the same 21w bulb for tail and brake. 

 

[GTSBoy]

It's very unusual. Taillights are usually 5W. Some are brighter at 12W. But a 21W globe is real brakelight territory. Brakelights are always much brighter than any permanently lit rear light, for obvious reasons.

I would be tempted to distrust the Narva et al listings and possibly being contaminated with false data from some common/root source. Go ask BMW directly perhaps?

[Duncan]

Not japanese engineering? Never seen that happen on a skyline ?

[PranK]

5 hours ago, GTSBoy said:

It's very unusual. Taillights are usually 5W. Some are brighter at 12W. But a 21W globe is real brakelight territory. Brakelights are always much brighter than any permanently lit rear light, for obvious reasons.

I would be tempted to distrust the Narva et al listings and possibly being contaminated with false data from some common/root source. Go ask BMW directly perhaps?

I did check a heap of sources. I'll email my local BMW service and see what they say.

[niZmO_Man]

It should tell you in your handbook? But yeah that's too much heat/current (too high wattage bulb)

side note: https://www.newtis.info/tisv2/a/en/

[Duncan]

32 minutes ago, PranK said:

I did check a heap of sources. I'll email my local BMW service and see what they say.

lol, won't he tell you to f**k off, he's drunk

[PranK]

Well I checked my handbook and can confirm all bulbs in the rear are 21w.

 

So, back to my original question, what would cause the housings to melt? Maybe a 100w house bulb? ?

[GTSBoy]

Can only imagine that the BCM runs the 21W globes that would normally be 5W in any other car at a reduced voltage, and perhaps this system has failed and is putting more (ie, 12) volts onto them and they get hotter than intended and do the melty dance.

[niZmO_Man]

I reckon it was an LED bulb and the heat sink sat against the housing.

[PranK]

On 01/10/2020 at 3:12 PM, niZmO_Man said:

I reckon it was an LED bulb and the heat sink sat against the housing.

But both sides from 2 cars?

[niZmO_Man]

On 07/10/2020 at 10:34 AM, PranK said:

But both sides from 2 cars?

Then that's a design flaw