I installed a alpine power amp - keeping the factory head unit. It sounds much better but I lost the illumination of the buttons on the head unit. I used the Metra connectors and matching the colors and adding wires to connect with the amplifier. There is 12 volts going to the head unit on the orange and white connector but no illumination of the buttons. 2012 Prius v, no JBL, with nav.
What color is the wire coming out of the factory harness on the opposite side, not the side you plug into? I would contact Metra for troubleshooting. Also make sure the illumination still works with the factory radio.
Discovered and fixed the problem. The Metra male connector (Metra 71-1761, 70-1761) for the rear speakers had four wires and the female had 5 wires. The orange with black stripe provides the power for illumination. I tapped directly into the wiring harness and all worked. The did not appear to be any documentation on what the extra wire did but I noticed it was on male connector of the toyota harness which plugs into the radio
