An alternator is an essential component of a car's electrical system. Its main function is to provide the power supply to the car's electrical systems and recharge the battery while the engine is running.. The alternator connections diagram typically illustrates the wiring connections and terminals on the alternator itself. These connections include the primary power input terminal, usually referred to as the B+ terminal, which receives power from the battery.
This wiring configuration will excite the alternator to start charging when the engine is running at low RPM's. There is a diode in the coil wire that prevents battery drain when the engine is of and also allows you to turn of the engine which can be a problem on some older vehicles with on and of ignition switches.. General F150 Discussion - Alternator/Starter wire from battery - On my 2011 FX4, I understand the heavy wire leaves the alternator and joins a similar cable from the starter on the fender, another wire leaves the fender and goes to the battery. What wire at the battery is the wire from the fender?