I have a 1976 bmw 2002.What does it mean when your reactor service light comes on. anyone know?

Nuclear Reactor light?

try this thread. Its based on mileage apparently. I never had a 76 but there is a button or something you can hit in there to reset it

http://forums.bimmerforums.com/forum/showthread.php?t=474104&highlight=service+light

look for a box on the left front rail. There was a FAQ question about that recently too