How Do I Know If My Head Unit Is Faulty? If you suspect your head unit is faulty, look for signs such as unresponsive controls, distorted sound, or complete loss of audio output. Check the connections and fuses to rule out any issues there. A malfunctioning head unit in your vehicle can significantly impact your audio experience and overall driving enjoyment. From static-filled sound to complete audio cutouts, there are several signs that indicate your head unit may be faulty. Ready to get your music back? Keep reading to find out how. Why Is My Car Stereo Not. A systematic approach is the most effective way to diagnose the problem, moving from the simplest checks to more complex component failures. The goal is to determine if the issue lies with the head unit's power supply, its ability to receive a signal, or its capacity to produce and transmit sound. These protectors prevent damage to the components receiving power in the circuits and prevent the circuits from overloading with too much power. These include incorrect amperage.