How to Wire a Chevy Alternator | It Still Runs The GM alternator used in all Chevrolet models is easy to install, as it is connected using only a few wires. The alternator converts the engine's mechanical rotations into an electrical current using a pulley-and-belt system. This current is fed to the car's battery, charging it for later use. In newer Wiring a Delco (GM) Alternator - hartin Wiring an alternator . This diagram shows how to wire a Delco (GM) internally regulated 3-wire alternator. This particular model (10SI, used in the 1970s and early 80s) is the one you'll find on the generation of GM cars most often used in demolition derbies.