RE: Bulb Failure Dipped beam?????
Same thing happened to me twice in one year on my 99 s80. When I took it to the dealer the first time it turned out to be a burned out resister so they changed it for $40. When it happened again after a few months I took it to the dealer again and it turned out to be a burned out shunt so they replaced it for $120 parts and labor. So if the bulbs are not bad I'll bet you its ethier a burned out Resister or a burned out Shunt. Take it to the dealer and have them check it out.