Do you know that you even have them? 10 speakers refers to the tweeter, mid, sub in the front doors/dash, and the tweeter/mid in the rear side panels. Take out your rear armrest and squeeze your hand in behind the seat, and feel if you actually have speakers there. Rear subs were on the 13 speaker setup, and a center channel does not guarantee 13 speaker.
Here's a shot showing the rear speaker locations:
The subwoofer holes just have foam knockouts in them which of course have to be punched out to get to the upper shock bolts, which is why mine are gone. My 04 had the 10 speaker setup and my 03 has the 11 speaker setup. Neither had subs behind the seat.
There you go. According to those diagrams there should be a crossover splitting them off of the side panel speakers. Probably have to follow the wiring from one or the other. What are the odds that someone mounted them but didn't wire them up properly? Also, I wonder if they used the same crossover for front and back. I wouldn't think so, because the front mid is a 3" speaker while the rear is a 6-1/2" but you never know.
Thanks for the advice about reaching behind the seat to find out if their are any subs behind it LloydDobler. I just check and I dont have any rear subs, I thought I did because I had the center channel speaker and the 400watt amp but no rear subs.
I am in the process of planning my sound system dos anybody know how much power the amp for the center channel has and the Ohm load it runs on? I read somewhere that their was an amp for the center channel that was located behind the radio, like I said just trying to plan my sound system, I have a phew ideas but I haven't purchased any gear yet. I am planning to sound dampen the doors, rear seat area and behind the dash first.