1999 mazda millenia amp turn on?

Hey everyone! I have a stock 1999 Mazda Millenia. I spent 5 hours last night with my friend installing a 500watt amplifier (no-name generic amp, probably does 300 watts) and a small ported sub. We had a hell of a time running the wires. But I searched everywhere online and all of these forums, I can not find out what wire i can tap into for amp turn on. The Antenna is built into the rear window! I found the factory amp wire hanging from the rear deck, but i didn't want to mess up too many wires finding it. Can someone please tell me what wire color to look for and where? Thanks!

When you said you found the factory amp plug but didn't want to mess it up.  Do you have a volt meter?  Turn the radio on, and test each wire in that plug.  When you find a wire with 12 volts on it, turn the radio off, if the 12 volts on that wire goes away when radio is off, that would be the wire.

I second what i am an idiot said, or use the pink/green (accessory) found behind the radio (or possibly at the amp too). Good luck with your install and welcome to www.the12volt.comrtfm

i am an idiot wrote: When you said you found the factory amp plug but didn't want to mess it up.  Do you have a volt meter?  Turn the radio on, and test each wire in that plug.  When you find a wire with 12 volts on it, turn the radio off, if the 12 volts on that wire goes away when radio is off, that would be the wire.

See, I couldn't find any, they all appeared to be constant power. I'll go through them again, it is only what i suspect is the amp, otherwise, why would there be a plug under the middle of the rear deck doing nothing at all?