How can I get my stereo to work in my new 2005 Chevy Cavalier?

I have a used 2005 Chevy Cavalier. I tried installing my Kenwood KDC-MP142 CD receiver up to it, and I am having problems. I have installed 3 stereos in cars before, including this one in another car, and never had a problem before. The problem is I need an adapter for the antennae, which is too small by default for my deck. I have ordered one, but it hasn't arrived yet. And that when I hook up everything but the antennae, the deck doesn't work. I know the wiring diagrams are right, and that my deck works. So I checked the stereo wires for power with the car off, and with the key turned to the accessories position. And none of them show as having power running through them, including the orange one, which according to the Haynes book wiring diagram for this car should be battery power. The even weirder thing is, the deck that was in there when I bought the car with no face plate, or the CD changer that goes with it, had a blinking light before I took it out. So how the heck was it getting power? This is beyond me, and very frustrating. The only thing hooked up to that deck not hooked up to this one was the antennae itself, which as far as I know gives no power to the deck. Would the deck not function without the antennae connected for some reason? And why do none of the stereo wires show up as powered? I used two different light up upon reading power type testers, and I know at least one of them works. Any insight or help with this problem would be appreciated, thanks.