My sisters Mustang is a 2007 v6, now, she wants to keep the stock headunit, and add an amp, and such...

I've already built her a fiberglass enclosure for the back right corner of her trunk, and got all the wiring ran, (ground, power, RCA, speaker wires, turn-on,) now, my question is... since she is keeping the stock headunit, which wire in the ignition switch wires do I use, I tried the battery, and well, overnight, it killed the battery, it drew more of a charge than I thought it would...

Should I look for an accessory wire? If so, what color is it on the 07s?

Thanks for any help.

 

Whenever I need help with wire colors and what they do, I call 'Crutchfield'. You can get their number from their website.