For over two years I had a problem with my 2009 Volvo S80 sedan dipped lights. I took the car to the dealer who first changed the bulbs and later claimed that we should change lighting system. Having diagnosed the system, the dealer company said the dipped lights normally when using entirely new lights head.

Fortunately, I got a solution from a thread from this forum that most lights problem are caused by a faulty ballast. I ordered the ballast from Sword at oemxenonshop. All my car lights are now working perfectly.