There can be several potential reasons why the volume knob in your car may stop working to adjust the audio volume level. Here are a few possibilities:
Mechanical or electrical failure: The volume knob itself may be physically damaged or have an internal electrical issue that prevents it from properly adjusting the volume. This could be due to wear and tear, a loose connection, or a malfunctioning component.
Wiring or connection problems: There could be an issue with the wiring or connections between the volume knob and the audio system. Loose or damaged wiring can disrupt the signal and prevent the volume control from functioning correctly.
Software or firmware glitch: In some cases, the volume control issue may be related to the software or firmware of the car's audio system. A software glitch or a firmware update that didn't install correctly could cause the volume knob to become unresponsive.
Faulty audio unit: The problem might lie with the audio unit itself. If the internal circuitry or components responsible for processing volume control signals are faulty, it can result in the volume knob not working as intended.
If you are experiencing issues with the volume knob in your car, it is recommended to consult a professional car audio technician or contact the manufacturer or authorized service center for assistance. They will be able to diagnose the specific problem and provide the appropriate solution or repair.