Headlight problem

Sounds like a classic 'bad earth' problem.

Less likely is an alternator on the way out and putting big spikes onto the
+ve supply. I'd imagine you'd have a lot of other electrical problems
though.

Is it always the same bulb that blows? If so it points to the wiring to
that bulb. If not it could be an earthing problem at the battery.

Al.

Were the bulbs checked for an open filament once they were removed? A
wiring or socket problem can look like a bad bulb when in fact the bulb is
still serviceable. Simply fiddling with the connectors in the process of
removing/replacing the bulb can cause the fault to disappear for a time.

I wouldn't expect that to cause early failure of the bulb. If there's a
ground problem I'd expect the bulb to burn dim or not at all. Since the
filament temp would be lower one should get excessive life out of the
bulb.
Yeah, there should be a lot of other problems if the voltage regulator was
faulty and allowing spikes.

It is possible that the bulb holder could casue this on a particular bulb
if it is loose and allows vibration/shaking of the bulb. I had that
problem on a 735 after repair of the rear of the car. The mounting area
for the tail light assembly didn't exactly match the original shape. This
allowed a slight rocking of the assembly and short bulb life. A bit of
shimming cured the problem, once I figured out what was going on.

--
The instructions said to use Windows 98 or better, so I installed RedHat.

It is the same bulb every time, yes.
Also I do have a very loud music system which I very much enjoy so its
always up when im driving.

Thanx for replying :-)

...
Snip
I'll let the other experienced DIY'ers 'splain the electrical mysteries.
How long between failures? You probably know this, if not, you do now, but
when replacing bulbs, care should be taken to NOT touch the new bulbs with
your bare fingers. Residual oils from your fingers fry under the intense
heat of the bulb, causing hot spots and early bulb failure. Use clean
gloves or extra care not to touch the glass.
Stan Chang
97 528iA
01 Z3 3.0L 5-spd

You haven't installed a "high output" HID look a like bulb, have you? The
owner of my BMW before me did and it melted the inside of the bulb mount. A
$18 part, a couple of clicks and I had my lights working fine again. Check
inside to see if the bulb holster looks melted.

Deep

Not always true, the stuff that vaporizes off the filament can condense
on the bulb glass rather than back on the filament like it's supposed to
if it's running to cool. Ideal would be, say, 12-14V

nate

--
replace "fly" with "com" to reply.
http://home.comcast.net/~njnagel

It is always a standard bulb, installed carefully, I think it must be down
to this "bad earth" thing, how can this be fixed? how does one find this
problem on my own?

Thanx people

You stand to cause electrical problems in your car if the add-on "loud
music system" draws more power than the alternator and battery can
muster. If your music system is really high output it can easily cause
an overload on some circuits and overheat them. It may be a classic
BROWN-OUT scenario.

You can look up other sources of information on this but the general
advice is to make sure you know the power draw of your upgraded system
and to make sure it can be handled without problems. Aside from bulbs
it can wreck the control circuits of other electronics in your car. Be
very careful -- if the lights dim (or blow) when you turn up the volume
it is definitely a very bad sign.

If you are playing the radio so loud that it is blowing the headlamps out,
maybe you should try turning it down a little. I am almost 100% positive
that nobody else likes your music anyway, and if you can extend the life of
the headlamps, then there are two reasons to turn that shit down.

Having been the smart ass, I don't think your music is the problem. I
suspect you have simply gotten a bad bulb or two. One thing to be ABSOLUTELY
sure about is that you do not get fingerprints on the bulb. The glass gets
very hot, and the oil from your fingers will cause the glass to break. If
you must touch the glass on the bulb in order to remove the bulb from the
packaging, then you must clean the bulb with alcohol before you install it.
Get some 71% or higher isopropyl alcohol from the drug store, and clean the
bulb before you install it.