thank you all so much! problem found! the black one is not ground, but the white/black is ! I have been following the wrong information from another webpage, saying that the black one is ground !
I just tested the blue/yellow (the battery wire) and the white/black, the reading is 12V ! while the original radio is disconnected.
I just tested the blue/yellow (the battery wire) and the white/black, the reading is 12V ! while the original radio is disconnected.