OEM headunit to aftermarket: New wires?

[derburger]

This weekend's project has been taking out the OEM Becker Mexico radio and installing a Pioneer Premier 690UB. I removed the Becker from the dash slot and the amplifier from behind the glovebox, and removed the cable between the two of them. I snipped the wires at the fader and routed them back to the slot in the dash, removed the splices that joined two sets of wires together. The wires sticking out of the dash are the 8 speaker wires, a keyed hot power wire (also connects to cigar lighter) a ground from the old becker, and the antenna.

My new headunit has one wire to the Battery, one wire to keyed hot ignition, one to illumination. The old becker did not have a dimmer, so I assume that if the illumination wire is not attached to anything there will be no backlight on the headunit. I'm thinking of connecting 8 gauge wire to the Positive terminal of the battery to the Battery wire of the headunit so the unit's memory isn't lost.

My question is this: After connecting a wire between the positive terminal of the battery and the battery cable of the headunit, would I splice a wire from the new battery cable to the 12v illumination wire on the new headunit? Also, is the keyed hot wire that used to attach to the Becker safe to use with the new headunit attached to the ACC wire? And, will 8 gauge power wire be good to use to attach from the battery to the headunit? And, I will be grounding the new unit at the bolt near the shifter where the shifter's light is grounded, should I then just tape up the ground wire that used to be attached to the Becker? The audio forum's old posts have been a great help but posting there would probably yield no posts. Thanks in advance for your clarification.

I've seen old becker Mexicos sell on eBay for 150+ dollars. Crazy!

[jcyuhn]

On every modern head unit I've seen the illumination wire is used to trigger dimming of the display, not to illuminate the display. Double check the wording in the manual for your new head unit. I suspect you'll be fine just hooking up the existing illumination trigger wire to the head unit. Everybody runs the dash full bright so it should be sufficient to trigger the radio display to dim.

Running 8 guage wire sounds like significant overkill. A headunit with built in amp doesn't draw that much current.

- JimY