An alternator is a car part that transmits power from the fuel system to the battery to operate vehicle accessories, such as the radio, headlights, and air conditioning fans. A wire called an exciter generates the voltage necessary for an alternator to start working once a vehicle is started.
Description: alternator exciter
Generally, three cables are connected to an alternator, including the exciter cable. The exciter, which is a low-voltage generator that transmits direct current, sends electrical current directly to the alternator.
Malfunction: alternator exciter
If the exciter cable is disconnected or malfunctioning, it will not transmit voltage to the alternator, and as a result, the alternator will not generate enough power to operate the accessories. Initially, alternator failure may not cause any symptoms as a vehicle’s battery has some reserve power, but eventually, the reserves are depleted and accessories such as the radio and air conditioning will stop working.
Exceptions: how to run an alternator
The alternators in most modern vehicles have internal voltage regulators; therefore, they do not need a driver cable to function properly.