You need this book!

This is a VERY comprehensive manual, this covers everything you'll need to troubleshoot the electrical system of a Bullet or modern fuel-injected motorcycle.  You will find: ignition and combustion explained, spark plug types and construction, ignition, magnetos, coils and batteries explained, CDI, transistor, and digital fuel-injection, engine management, alternators, DC generators and starters, lighting and signaling, braking and traction-control systems, electrical fault-finding, practical testing and test equipment.