If your car stereo is not working, you can perform the following checks for repair: 1. Check the speaker fuse: Start with the easiest step. If the fuse is blown, simply replace it. 2. Check the speaker relay: Most modern cars have a speaker relay. For the speaker to work, the relay must function properly. You can swap a relay from another part of the car to test if the speaker relay is faulty. 3. Check the speaker switch: Some cars do not have a speaker relay. If the speaker isn't working, the issue might be with the speaker switch. You can use a multimeter to test it. If the switch is easy to remove, you can also try installing a new one. 4. Check the clock spring: The clock spring is a component under the steering wheel that contains the speaker wiring harness. If there's a break in the wiring here, the speaker won't complete the grounding circuit and won't work. Replacing this part is complex, so make sure to diagnose accurately before proceeding. 5. Check the speaker: Most speaker failures are due to the speaker itself being faulty. Use a multimeter to measure the voltage at the speaker plug. If the voltage is 12V when the speaker is pressed, it indicates a speaker fault, and you should replace the speaker. 6. Check the speaker wiring harness: The speaker wiring is relatively simple. You can refer to the circuit diagram to trace the speaker wiring and test each section, or directly locate the wiring harness in the car and use a multimeter to check the continuity of the wires to find the fault point.
