Electrical System Overview The BMW /2 motorcycles have what could be viewed as two electrical systems - one for the engine(ignition), and one for all the extras such as lights and the horn. The ignition system consists of the magneto, coil, points and the sparkplugs. The ancillary systemincludes all the bulbs, the battery, generator, horn, and switchgear. Because of this separation, it is possible for the engine to run quite happily despite major faults in the restof the wiring system. Early electrical components weren't very reliable, and this was a major reason whymany vehicles, and motorcycles in particular, had this kind of separation. However, after the Second World War, other vehicle manufacturers started moving towards the coilsystem of ignition, and integrating the electrical systems together. BMW remained with the split electrical system for some years, only changing to coil ignition and a singleelectrical system when the /5 motorcycles were released in 1970.