Can't get head unit to dim with instruments

[Guard Dad]

My newly installed Pioneer AVH-P4300DVD head unit works great but I'm still trying to get the illumination correct, it's full bright all of the time. I'm using the Orange/White wire (this is labeled as "illumination") on the Pioneer's receiver cable which is connected to the Orange/White wire on the Scosche connector which in turn connects to a red wire on the factory connector.

What am I doing wrong?

The car is a 2010 base model/sport package/ AT7 and all the speakers have been replaced and all of the speaker wires have been replaced.