Hello. What vehicle are you referring to? Also, what lights are you referring to? If you are referring to an e32 and your problem area is headlights, your LKM or Light Control Module may be faulty. Just a thought.
If its the headlamps then it does sound like the LKM. This is the black unit about the size of a VHS video tape which handilyhas LKM stamped on the side. It's possible to strip and resolder this item and it should cure your woes. There's a more detailed explanation on this site I think http://bmwe32.student.utwente.nl/