My A6 Headlights keep blowing approx every month

[Th11sworks]

I've had my Audi A6 (W reg) for approx 2years. Not once has it given a problem until recently. For the last few months the headlights keep blowing individually. I have had them replaced and made sure the mechanic is putting them in correctly. He has pointed out you can't put them in any other way. The bulbs being used are Bosch premium bulbs.

Can someone please advise as it is really killing me knowing there is a fault with my car. HELP!!

Thanks

[lonky]

Only 3 things cause bulbs to blow early.

1) grease on the glass, from fingers during installation
would not expect this from experianced mechanic

2) vibration
not lightly if both lights keep blowing, unless they have been removed and incorrectly replaced.

3) Over voltage - most common reason, though would expect other lights also to be blowing

check charging voltage is below 14.5v

[Peter D]

I have measured an A6 running at 15.25v eventually traced to a aged battery with a higher then normal internal resistance. However are you sure you are not hitting speed bumps too fast as this impact can cause prem bulb failure. Regards Peter

[Th11sworks]

Thankyou for all those that have contributed to this thread. The information has been very useful. I had previously thought it might have been the vibrations or possibly the alternator. I had the alternator checked and the current was border line. I think Peter D has nailed it though. My battery died on me a few days ago, which I have now replaced. If Peter is correct about a dying battery contributes to the bulbs blowing then we have identified the cause. I reallyu do hope so. We shall See.

Thanks