I'm installing the Z3 into a Silverado SS and have had the ILL wire hooked into the Illumination wire on the GMOS unit and made sure that the daytime / nighttime was set to automatic. The unit never dimmed or turned the picture color over (on my old N2 the land on the map turned to brown at night time instead of white). Yesterday, I broke into the wiring again and hooked the ILL into the Dimmer wire instead and turned the headlights on, again checking that daytime/ nighttime was set to automatic. It still didn't change the color over.
Can someone give me a definitive answer to what the correct wire is? I've seen some posts on here saying dimmer wire, and others saying illumination wire (maybe it's vechicle dependant?). Neither seems to work for me. Thanks.