Hi mate! Thanks for the video. I have a static sound through the speakers with mine when the radio is turned off. Just wondering if yours was the same?
No, not on ours. So it's when the radio is "off"? Is it all speakers or just one? Try the Balance/Fad to establish the effected speaker(s). Then perhaps use a volt meter on the output pins on the back of the radio head (for the relevant speaker) to establish if the power is coming from the radio (whilst off). This might establish a radio head fault or suggest a wiring fault somewhere on the loom.
