I looked at a lot of past threads trying to figure out the specific wire(s) that I need to tap in to in my '05 for the light circuit on my cyberdyne gauges. My understanding is that the wire that I tap in to should decrease the normal light emitted from the digital display, so I don't need the normal illumination circuit for dash lights. I have a wiring harness adaptor from Crutchfield that my Alpine IVA W205 is connected to. There is an Orange/White wire from this harness that is labeled "dimmer". When I hook the cyberdynes up to this, the digital lights start pulsing on and off. Does anyone have an idea as to what wire to tap in to? If so can you be specific as to color, location etc?

 

Kind of confused as to exactly what you are looking for. Just a dimmer wire? Like you said behind the radio there should be a dimmer wire in the factory plug that may work. Do you have the radio dimmer wire hooked up also, when you are trying the guages (that may be causing a pulsing issue - had a radio a few years ago that pulsated when the dimmer wire was hooked up to the dim wire in factory harness). If not check wiring at the headlight switch panel for a dimmer. Not sure of any other wire that would allow you to solely "dim".

I know when I hooked up my Nav the dimmer wire on the back of my radio didn't like the dimmer wire in the factory plug, so I just ran it over and hooked up to the switched parklight wire so the radio would go to day/night mode with the headlights on/off accordingly.

 

If this is what you are trying to do...
3. Connect purple wire from gauge to the night time dimming circuit. (The purple wire must be connected to the headlight switch circuit so that there are 12v to the purple wire when the headlight switch is on and no voltage when the headlight switch is off)

I would do what I did in the 2nd paragraph above.
Be sure to test first.. brown wire + at light switch

 

I first wired the purple wire to the light wire (blue w purple stripe) that runs the night light on the switch that controls the backup sensor. I have a quartz analog clock that also has it's night light connected to this wire). When I made this connection...I got the stobe effect on the digital gauges. I then tried the 'dimmer wire (orange w white stripe) on the radio harness that is not being used by the headunit. Again, the digital gauges gave the strobe effect. Maybe since both of those wires go through the 'dimming' circuit they are not getting a true 12V and this causes the strobe? I will give the headlight wire a try after I confirm that it (the brown one) is switched. Thank you for the response. I still wonder what is going on inside the gauge...one would think that the dimmer wire would somhow reduce the voltage to the led lights in the gauge and dimm them....I guess this isn't how they work.