on the d3 i see we have a feature for daytime nav. screen, and a night time nav. screen. When i switch between the 2 screens i don't see any differance at all. Am i missing something? Does anybody have any pics to show the differance??.....my 05 chevy colorado has daytime running lights, would that have anything to do with it?
PEACE
That's probably what it is. The daytime nav has a white map background while the night time nav display has a grey map background. If you are turning your headlights on and off and see no difference in the display, the daytime running lights might be causing the D3 to stay in night time mode always.
Check this out, it might help: (Someone having the same problem with a similar GM truck)
I believe the daytime setting keeps it in dt mode the whole day. Nighttime allows it to switch, as long as you have the illum. wires hooked up properly. 
I've seen this Q a few times and meant to verify this by toying with it for a few.
on the d3 i see we have a feature for daytime nav. screen, and a night time nav. screen. When i switch between the 2 screens i don't see any differance at all. Am i missing something? Does anybody have any pics to show the differance??.....my 05 chevy colorado has daytime running lights, would that have anything to do with it?
PEACE
I had this same problem with my 05 Sierra! Disconnect the orange/white illumination wire that comes out of the D3 and either find the wire in the stock wire harness...or you can do like I did and run a jumper wire over to the headlight switch. Run it behind the cluster and find the wire in the switch that triggers when the lights are on/off. In order to know this, in the NAV Menu there is a choice for "Connections" I dont remember exactly how to get there but once you find it, it will show you the GPS antenna strenth, and down at the bottom it says Illumination on/off.
Anyway, I figured this out by inspecting the Metra GMOS-04 harness. The dimmer and illumination wire coming out of this harness do not match up correctly. The illumination wire doesn't meet up with anything at all in the stock harness!
Hope this helps.
i have a gm yukon, the installer hooked my illumination wire into the on and off or auto swith its self , and now the d 3 works with my auto headlights.
Thanks for the help on this guys....i think i will go back to my installer and see what he thinks....i just wanted to make sure i wasn't missing something.
PEACE
DRL's have nothing to do with headlights or illumination. A quick way to find out if you plugged your illumination wire into your DRL circuit is put the e-brake on and start your vehicle and put it in drive, then release the e-brake if your screen changed then you are somehow tapped into the DRL circuit. There aren't any wires from that circuitry to the back of the radio though, the wire you want to hook into is called the "instrument panel lamp supply voltage" I will try to find the pin out for you.
Here is what you are looking for:
pin: 4
wire color: white
Headlamp Switch Headlamps On Signal
This is located on the headlight switch. Here is the plug
Thanks alot for all your help.....i'll be looking into this.