| Author |
Message |
    
zebedee2001
Member
Username: zebedee2001
Post Number: 10
Registered: 11-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, 06 February, 2010 - 08:01 pm: | 
|
Not strictly electronic but I know what clever people you all are! Here goes, I have been having problems with the rear lights on my car. The bulbs do not last too long (a couple of years max). Instead of the filament blowing the terminations inside the bulb appear to be corroding/burning away. What causes this? I should be able to post some pics tomorrow!
Any help would be appreciated! |
mikehibbett
Frequent Contributor
Username: mikehibbett
Post Number: 1097
Registered: 04-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, 06 February, 2010 - 08:29 pm: |
|
I'd guess that the connectors that plug onto the bulb are worn, and giving some resistance. This would cause the termination to heat up.
Just a wild guess. I can't imagine any other reason, unless you have a consistent poor quality bulb supplier ( less like IMHO )
Mike |
twintub
Frequent Contributor
Username: twintub
Post Number: 62
Registered: 02-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, 06 February, 2010 - 10:01 pm: |
|
As the corrosion is INSIDE the bulb, it would suggest poor quality bulbs! |
ant
Frequent Contributor
Username: ant
Post Number: 575
Registered: 05-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, 06 February, 2010 - 10:17 pm: |
|
In case Zebedee meant "inside the bulb holder" - I had this trouble with my Volvos, I used to put more (leaded)" solder on the terminals. A smear of Vaseline would probably also have helped but it gets sticky.
Regards Ant |
zebedee2001
Valued Member
Username: zebedee2001
Post Number: 11
Registered: 11-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, 07 February, 2010 - 05:24 pm: |
|
OK, now got some pictures
bulb1.jpg shows the "corrosion" affect I was talking about
bulb2.jpg shows the corrosion as it gets worse, erroding the left hand terminal away
bulb3.jpg shows a bulb I discovered where the crimping of the element had started to lift (see right hand terminal)
Any ideas what is going on here? |
joe
:::: Super User ::::
Username: joe
Post Number: 738
Registered: 05-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, 07 February, 2010 - 06:50 pm: |
|
I think they are cheap bulbs. You should contact the maker and complain.
I've had two break/side light bulbs where the the metal support wire connected to the break element would bend as it got hot and short out to the side-light support wire. This meant that when I turned on the side lights at night and then used the breaks, eventually as the bulb warmed up, the break light stayed on all the time. Annoyingly, when I pulled up at home and turned off my lights, hitting the break caused the dashboard lights to come on; that was the clue to what was going on.
Took me flippin ages to get it sorted and I gave the makers hell over it; I had the electrical system in pieces looking for a faulty switch or short circuit; water ingress etc.
They sent me a box of 10 replacement bulbs to say sorry.
Joe
Read my ramblings - www.techbites.com/joe-farr
|
hackinblack
Frequent Contributor
Username: hackinblack
Post Number: 454
Registered: 09-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, 07 February, 2010 - 07:14 pm: |
|
that does look strange! but,as the bulb is a sealed globe there shouldn't be any way for corrosion to get INSIDE...
if it was getting overvoltage from a failing voltage regulator it would almost certainly blow the filament and blacken the glass inside,
i've seen this happen if the bulb seal fails too(one mains powered lamp actually exploded!)
the crimped end inside uncurling looks like the whole bulb is running too hot;or maybe just poor quality bulbs.
the point made about checking the spring terminal touching the bulb base is a valid one; some light cluster contacts are prone to losing their 'springiness'
some of the ones on the volvos had poor crimps on ALL the blade connectors,ive seen several fuse holders etc. almost charred by the heat,out of sight,naturally
any connection with corrosion or poor contact will dissipate almost as much heat in the connector as the load its supposed to supply |
twintub
Frequent Contributor
Username: twintub
Post Number: 63
Registered: 02-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, 07 February, 2010 - 11:00 pm: |
|
Hackinblack has hit the nail on the head!
Maybe the seal is bad and a small amount of oxygen has entered and has caused the rusting that can be seen in bulb1.jpg.
The presence of oxygen may also have caused the filament to burn hotter which has resulted in the crimps unfurling and the support posts bending.
Oxygen in a mains bulb will cause its fragile filament to burn-out immediately, but car bulbs have a fat filament which can withstand the extra heat for quite some time.
Prognosis: Poor quality bulbs from China or the likes! |
zeitghost
Frequent Contributor
Username: zeitghost
Post Number: 1433
Registered: 01-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, 08 February, 2010 - 08:19 am: |
|
Brings back memories of a 1970s era Halfords bulb.
Lasted all of 30 seconds when I pressed it into use in 2002. |
741
Frequent Contributor
Username: 741
Post Number: 133
Registered: 08-2005
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, 08 February, 2010 - 02:18 pm: |
|
For some household bulbs, over several years and different lampholders, I've sometimes had to take the entire lampholder down just to release the bulb. The holder contacts seem perfectly free to move, but the bulb contacts seem to be melting..
 |
zebedee2001
Valued Member
Username: zebedee2001
Post Number: 12
Registered: 11-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, 08 February, 2010 - 08:23 pm: |
|
The bulbs in question are from two manufacturers Ring & Osram.
A slight aside, I was once told by a friend that the police check the brake light bulbs in some car crashes to see whether the filament is intact. If it is it suggests that the person was not braking during the impact! Don't know how true this is... |
kevinbrunt
Frequent Contributor
Username: kevinbrunt
Post Number: 89
Registered: 02-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, 08 February, 2010 - 09:22 pm: |
|
Checking the bulb filaments after a crash is a common procedure, even more so for plane crashes. A hot filament stretches under the G forces. It can be a way of determining what lights on the instrument panel were lit. |
twintub
Frequent Contributor
Username: twintub
Post Number: 65
Registered: 02-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, 08 February, 2010 - 09:45 pm: |
|
@zebedee2001
These are surprising failures for such prominent brands. Did you buy them from a reputable dealer? - I was wondering whether they were fakes! |
ant
Frequent Contributor
Username: ant
Post Number: 578
Registered: 05-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, 09 February, 2010 - 10:15 am: |
|
Hello all,
Part of the problem of course is that solder creeps under pressure, that's why one shouldn't tin wires for use in terminal blocks.
Regards Ant |
Closed: New threads not accepted on this page
