H4 Light bulb question

[Falcon_LS]

I got H4's on my truck, and tonight I noticed my right headlight is out. The strange thing is, however, the high beams are working. Is this a problem with the bulb, or something else?

I've never replaced the headlight bulbs in the 10 years I've owned this vehicle, but a couple of months after delivery I installed European Sylvania Silver Stars. They've been there since. Wouldn't be surprised if their time has come...after 9 years!

 

[Smokescreen]

Inside the H4 there are 2 elements. You simply burned out the low beam element.

From http://www.danielsternlighting.com/products/products.html ...

""" H4 bulbs
These 2-filament bulbs with P43t base are for high/low beam headlamps and Cibie BiOscar fog/drive beam lamps. Fun facts: The H4 was the world's first 2-filament halogen automotive bulb. It was introduced in Europe in 1971, and was used in many millions of European and Japanese headlamps starting in that year, but wasn't legalized in the US (where it was designated HB2 or 9003) until over two decades later, in 1992! """


The other shouldn't be far behind. I would replace both bulbs at the same time to keep intensity and lifespan more equal.

The Euro Osram Silverstars are a quality unit. If it were a garbage North American version of the "Silverstar" you would've had to replace it 9 years ago and every year thereafer...

 

[Falcon_LS]

Thanks for the response. I'm going to have to go with OEM Osrams this time round...I bought the Silverstars from the UK and they were excellent bulbs - brighter than the OEMs. Will have to purchase another set when I go back.

 

[Falcon_LS]

Well, I replaced both bulbs with European Silverstars again. They were a bit pricer than what I paid for them in the UK 9 years ago, but they're well worth it. These are great bulbs!