Which of the following are common signs of a failing alternator?

Dimming lights, a dead battery, and electrical issues are indeed common signs of a failing alternator. The alternator's primary role is to recharge the car battery while the engine is running and to power the vehicle’s electrical systems. When the alternator starts to fail, it cannot provide adequate voltage and current, leading to various electrical problems.

Dimming lights, for instance, occur because the alternator isn't supplying enough power to the headlights and other lighting fixtures. These lights may glow brighter when the engine is revved up, which points to fluctuating voltages from a faulty alternator. A dead battery can result from the alternator's inability to replenish the battery's charge, especially after extended use of electrical devices when the engine isn’t running. Additionally, other electrical systems, such as the radio, dashboard lights, and power windows may exhibit erratic behavior when the alternator is on the decline.

Other options mentioned do not align with the typical symptoms of a failing alternator, as they relate to different components or issues within the vehicle.