Hi,
My wife`s 95 850 seems to go thru headlight bulbs fairly quickly, ie, about 3 months or so. This car has DRL`s so maybe this accounts for the short life span. She has been using the bulbs from the dealer, I think they are Sylvania bulbs.
Is this normal or should we should be switching to another brand?
Thanks,
Rich

Check the voltage regulator.

Electrical connectors are frequently of questionable reliability in Volvos, especially where a high current (as in a headlight) is present. Make sure the connectors are free of corrosion or deposits, as this increases resistance (which increases heat, which...you get the idea. You might by new connectors (with wires attached) just to be sure. Spray with Tri-Flow or same other electrically conductive lubricant/protective coating.
--
(98 S70 T5SE misc mods, mostly lighting) (92 940GLE)

This is not normal for an 850. Our 95 850 lost its first headlight bulb
last week and we use the DRLs all times (one brake light since new, too).

You might also have the electrical charging system checked to make sure
it is not over voltage.

Does the same side fail or does it happen to both sides?

I have the 94 850 turbo utilizing four bulbs... I haven't had ANY problems and have just switched to Sylvania Silver Star bulbs and like them even more...

Make sure there are no "holes" in each lens... and you might check to make sure that the light assembly is tight... these lights don't like a lot of harsh vibration when hot...

Probably wouldn't hurt to make sure that the connections are clean where the bulb plugs in... arcing would/could be another possible problem...

Shawn