My recollection of RCA plugs is that the center is + and the shield is -. This is how I hooked up my Pathfinder (with a similar install method) and it works perfectly. However, I do remember reading somewhere that, in SOME, cases you should just leave the shield connection out (can't remember where and if anyone thinks I'm full of it, you might be right...but I swear I read this somewhere). That drawing doesn't show an Amp Remote Turn On connection...do you have that connected right?

As for the crossed speaker...got me?