Left Hand Low Beam Globe keeps blowing (Halogen)

[HWR]

Hi Everyone,

I'd appreciate some ideas on a persistent problem my X5 is having.
It's a 2005 3.0D Right Hand Drive.

The Left headlight is continuously failing, the vehicle is fitted with Halogen globes as standard.

A few months after purchasing the vehicle the LH Low Beam globe failed. I replaced the globe with another Halogen but the replacement blew about 4 months later.

Unsatisfied with the light out put when the second globe failed I decided to install Xenon HID kits to the lights. This was about 12 months ago

Subsequently I have had 3 Ballasts fail in the LH Low Beam, the last ballast was connected to battery power via a relay that was triggered from the factory headlight wiring.

After the third ballast failed a few months ago I went back to Halogen globes in the Low Beam lights out of frustration. The globes that I installed into the Low Beams were both New.

The LH Low Beam globe has failed again today.

This makes a total of 3 Halogen Globes and 3 HID Ballasts in the LH Low Beam that have all failed in under 2 years.

The RH Low Beam and Both High Beam lights have been working perfectly with no problems (the high beam still have the HID kits that were installed when I first did the upgrade 12 months ago).

Out of interest, the vehicles battery was replaced about 4 months ago and the alternator output is correct.



There is clearly a problem in the LH Low Beam somewhere but I'm at a loss as to what and where the fault could be.

Has anyone had a similar problem and what did it turn out to be?

Any assistance would be greatly appreciated.

[jdd]

As an electronics engineer, there can be a number of causes for this type of problem.
The most common cause is usually the light socket itself, but it can also be caused by a bad relay, or bad wiring/connectors to the light socket, or a bad/intermittent earth.
I’m not sure how you connected in the HID units but obviously the fault was still present during that time. If you used a separate relay as you mention, you can probably discount the original relay.
Was the original light socket used when the HID units were installed? If not, this would tend to point towards a bad/intermittent earth. If it was used I would point toward this as the most likely culprit.
These sorts of problems can be very difficult to find, particularly as intermittent as this one seems.
Sometimes it is quicker, and cheaper if you’re having to pay somebody to do the work, just to replace all the possible components in one go.