Ok I emailed metra, since I am using the Metra TOYO-01 harness. This is what they said:
"What you will have to do is take that wire straight to either your dash dimmer inside the car, or to one of your taillight wires as Toyota
does not use illumination on their vehicles, they use dimmer, positive and negative. You need a wire that will show twelve DC when the lights
are on, dimmed or not dimmed. You must use a digital multimeter when doing this as you can damage your dash light dimmer. Highly recommended to have a professional do this for you, and make sure they have insurance in case they damage the car."
Any suggestion on what to do??