If both an amplifier and head unit bench tested fine but show no left channel audio in the vehicle, what could be inferred about the RCA audio cable testing 0.01 Ohm?

The inference about the RCA audio cable, which tests at 0.01 Ohm, suggests that it is not functioning as intended. A healthy RCA cable typically has a much higher resistance in the range of several kilo-ohms when tested with a multimeter. The very low resistance reading indicates that the cable is likely experiencing some form of malfunction.

In this context, a reading of 0.01 Ohm could imply a potential short circuit or a severe fault within the cable itself. When both the amplifier and head unit are confirmed to be working properly during bench tests, but there is no left channel audio when installed in the vehicle, it supports the conclusion that the RCA audio cable could be the source of the problem, possibly leading to a complete loss of the left channel signal.

This reading indicates that the cable might have deteriorated to a point where it is unable to carry the audio signal effectively, which aligns with the symptoms observed in the system. Therefore, the most reasonable conclusion is that the cable is faulty.