illumination wire

[EKam]

Do I connect that to a 12v constant ?

So what it does basically is it dims the deck when you turn on the parking lights at night right?

[Phi]

not a CONSTANT!! r deck will be on ALL THE TIME!! Tap into the parking wire or any other wire that provides pwr when ur parking lights are on.

[mach_y]

actually, the illum wire on most decks gives the ability to dim the radio in the same way your dash is dimmed. It all depends on what type of signal your illum wire is expecting to see, and what you car uses. Some cars use a drain to ground, others a positive connection. It can be a serious pain to figure out which it is and where to tap in to make it work right. Putting on the parking brake lights will dim it (if it is the correct polarity) when they are on so at least it does something though.

[Silver Streak]

Not sure what deck you have...but try this link:
http://www.mounstronic.com/caraudio/kdcmp919.htm

"Display Dimming: This unit is equipped with a wire that Kenwood calls an illumination lead, however, it acts as a dimmer lead. When the illumination wire of this unit is connected to the headlamp circuit of your vehicle, and you turn your lights on, the display will dim to a preset level. The display brightness is not affected by the vehicle's dimmer control."

Hey, do your parking lights turn on immediately when your car is turned on? Mine do on my 92, not sure if it's the same for the Gen3.5. Heck all my lights turn on (except my headlights) when my car turns on.

[Xenon]

There's positive illumination and negative illumination.. My deck for example dimms when the headlights come on, so are meant to react to the dimmer dial on your car, so when you lower or higher the brightness of your interior lights it does the same.

Like Phi said, you should hook it up to your headlights or try to find something in your center console that lights up with your headlights and tap into it.