OK, I'll just start off by saying I'm a complete noob when it comes to all things audio, but I thought with some simple to follow instructions I could do this install but I guess not.....now I'm here to get the help of the experts.

Here's the situation -- simple setup with stock Sony CDX-M60UI head unit, an xi800.4 amp and two xm7 tower speakers. I got the power/ground wired up fine as I see the power light come on for the amp, but when I hook up the RCA cord from the amp to the head unit I get no lights on the amp telling me its getting a signal. Looked thru the Sony manual and I see nothing that tells me if there is setup or some setting I need to send a signal to the amp.

Any thoughts on what idiotic step am I forgetting (or worse, a step I didn't even know)?