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2016 Forester XT AT
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1,295 Posts
Discussion Starter #1
I did the H11/H9 low beam conversion yesterday and while doing that I could see that something was happening on the high beam bulbs:






These are 9005 GE Nighthawks, with about 40,000 kms on them (not all on high beam of course :cool: ). They still work but I wonder for how long, so I replaced them with new ones.

Any idea of what might cause this? The drivers side is the worst of the two but both show signs of this weird burning. The burnt part faces up btw, if that matters. And I know not to touch the glass part of the bulbs; I have been using these types of bulbs since the early 80's and have never seen this before.
 

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Ah crap.. I'm back with my 05 XS
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8,294 Posts
Whoa. Is the filament getting too hot and was possibly touching that side? Hmm can oils from your hand cause this once it's heated up?
 

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2006 Forester X
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15 Posts
If those have 40,000 kms on them, did you have them out of the housing while doing the conversion?

I'd bet those bulbs got touched (possibly accidentally) at some point with bare hands, or something else that left an oily residue behind. Since halogen bulbs run quite hot (in order for the halogen gas to do its job of keeping evaporated tungsten off the glass and redepositing in on the filament), any oils on the outside of the glass capsule can cause hot spots, which can lead to deformation and/or failure of the glass bulb.

I'd say replace those bulbs asap. I doubt they will survive much longer, and will only get worse. You probably don't want those failing (possibly exploding) inside the headlight enclosures, hot bits of glass on plastic will do some damage.

Steve
 

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2016 Forester XT AT
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1,295 Posts
Discussion Starter #4
If those have 40,000 kms on them, did you have them out of the housing while doing the conversion?

I'd bet those bulbs got touched (possibly accidentally) at some point with bare hands, or something else that left an oily residue behind. Since halogen bulbs run quite hot (in order for the halogen gas to do its job of keeping evaporated tungsten off the glass and redepositing in on the filament), any oils on the outside of the glass capsule can cause hot spots, which can lead to deformation and/or failure of the glass bulb.

I'd say replace those bulbs asap. I doubt they will survive much longer, and will only get worse. You probably don't want those failing (possibly exploding) inside the headlight enclosures, hot bits of glass on plastic will do some damage.

Steve
Already replaced as I have a long night drive (almost 800 kms) this week and did not want any issues. And no, they do not have to be removed to do the H11/H9 conversion. It was while I was looking into the headlight lens that I first noticed this. And funny that its on the top side of both bulbs, not like a random touch.
 

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1999 Forester
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40 Posts


May be a late reply but the reason for the above photo was not the light but the plug itself. After upgrading to higher intensity headlights many find that the actual plug could not take the pressure and started melting causing odd contact points and arcing which caused the bulbs to melt.
 

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Fast & Dirty
2009 Forester XT 4 speed auto
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4,039 Posts
When I replace bulbs I wear latex gloves (i have endless access to them. My business).

I have also worked on spectrophotometers. These are medical instruments that use halogen bulbs. The worse thing you can ever do is touch the bulb. I would clean the bulbs with alcohol and wipe with distilled water and let dry. Oil is not good.

Cheers
 

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2005 Impreza RS Wagon Auto
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3,658 Posts
Whoa. Is the filament getting too hot and was possibly touching that side? Hmm can oils from your hand cause this once it's heated up?
At Autozone we always warn customers about touching the bulbs yet many come back saying the bulb exploded/burned out. They show the bulb and I just laugh because they obviously didn't listen and blew up 45$ in bulbs. Your skin (and working surfaces) are more dirty than they seem.
 
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