Don't quote me on this, but I have the basic low end radio in mine and from what I recall the actual screen probably doesn't have a dimmer switch wire(again I might be wrong) . It's internal as far I can remember. The physical buttons might be the ones that might have a backlight dimmer switch connection. Try using the dimmer switch on ur vehicle ..this will tell u if it actually controls the screen backlight intensity. From what I recall just certain buttons are controlled by the resistor(might be a wrong term for this as Im more under the impression that it runs by an additional logic module) ..... backlight for the light switch, cup holder lights . steering control buttons, instrument cluster ..have a connection to this and possibly the radio buttons .. I'll check to refresh my memory in the next few days.
In short no, but that hardly matters, wire color can vary and usually changes between years .. best bet is, if u do pull it , use a tester light on the terminals . If the radio buttons are controlled by the same dimmer switch then most likely u will be looking for the same exact wire color as the backlight for the Light switch ,cup holder and etc. Be very careful not to cross the proboscis of the tester with any other wire or ground so not to create a short. It should be protected by a fuse but nevertheless worth mentioning.that u take precaution.
I myself was going to look into this but wasn't planing to do so for another year. I would try to use the same factory LED light to backlight any new accessories ..this would ensure there is no amperage and wattage issues to deal with but..sometimes this is not possible and will have to use something else.. Just a thought that popped up.. if u have continuity tester u can also use that for connection between the wires on the cup holder and one of the terminals of the radio... this saves a bit of time sometimes. Oh and one more thing ..if using the continuity tester pull fuse or battery connection to make sure there is no juice flowing through it.
Took a better look today. So this is what I understand now.. The resistor that dims the dash gauges , buttons , cup holder ..and so on , doesn't have a connection to the radio in the dimming position. However, it does have a connection to it in second position ...where it gives full brightness , just before the position where the interior light comes on. The dimming adjustment is in the radio unit screen itself and the switch can only illuminate by adjusting high to low but nothing in between like the other accessories ..again the buttons , gauges etc.. So u can adjust screen brightness and the related button (high to low only) with the resistor switch on the left hand side, but , any fine adjustments are made in the head unit itself. They are connected to each other in the second position of the dimmer switch by most likely the same wire.... I'm not sure if u'll be able to use this wire for dimming though.
