I am installing the d3 in my 05 corolla right now. I have two questions which probably seem stupid but want to make sure. On the corolla harness there are two wires orange/white and orange/black. On the avic there is only a orange/white (ILL) but, on the wiring chart on the back of the corolla harness package it says orange-illumination and orange/white dimmer. Thats confusing since thats technically not what wires are on the harness. According to charts it says these wires are "not used". What should I do? Just connect the orange/white to the orange/white on the avic?

I am only worried cause I read people on this forum mixing this up and their avics were not dimming and getting brighter when their lights are on/off.

Second:Do I ground the ground wire on the car harness to the g/w on the avic harness? or ground separately? Or do I leave the ground wire on the corolla harness alone and only ground the G/wire on the avic harness?

Thanks so much guys I can't wait to get this thing in

Test it before you put the car together. Sometimes the orange/white wire will not work on the avic depending on the level your dimmer is at. If it doesn't then there's a green/white wire in the harness that runs to the rear of the car on the driver's side. That's the +parking light wire. That'll work for an illumination tap.