Pin 10 triggers the radio backlights to dim when your headlights are turned on. Amazon.com To help you specifically, could you tell me: model and year is your vehicle? Are you installing an aftermarket head unit or repairing the factory radio Does your car have a factory amplifier (JBL system)?
The hardest part was the speakers. The diagram showed a complex color code: Pink for Front Left Positive, Violet for Front Right. The diagram on his phone showed them terminating at a connector block that didn't exist anymore. He had to hardwire it, relying on the color coding standards of the Fujitsu Ten factory prints. manual toyota fujitsu ten 86120 wiring diagram