Audio Systems: installing new amp into 97 Mercury Mountaineer, rca cables, oudio

Question
Hello,

I have a 1997 Mercury Mountaineer with the jbl premium audio sytem and I'm trying to install an after market amplifier and subwoofer.  I know how to install an amp, but I don't know where to make the connections in the premium audio system.  It looks like I can connect it to the receiver in the cargo area because the connections to the old amplifier come straight from it.  I don't know which are the power cables, ground cable, and remote turn on wires though.  I also don't know where to wire in the speaker connections either.  The amp does have speaker level inputs though, so I don't have to worry about rca cables.  If you could possibly provide me with a wiring diagram or something I think that would do the trick.  Thank you!

Answer
you can not tap in to the factory amplifier this unit is also the tuner  in thes vehicle  so be very carefull run your power to the front battery
also the unit at front is not a radio  don't remove or tap into any cables there  

to get the speakerinput for the amplifier use the subwoofer oudio from the factory 8 woofer
good luck