1999 Mercury Mountaineer OEM Audio System

I just bought a 1999 Mercury mountaineer and the OEM head unit display does not come on, I cannot adjust the Bass and Treble, and the sub woofer does not come on. When I took it down, I found a High/Low impedance adaptor, wires that where spliced incorrectly, and after further examination, I found the remnants of (mostly 10AWG wire) an aftermarket amp and sub system. What I want to do is rewire everything behind the head unit before spending $400 on a new OEM head unit and having to replace it repeatedly, because of bad wiring. Therefore, does anyone have a complete diagram of the audio system? I think it is the Mach premium audio system. It has a 6-disc CD changer and rear passenger audio controls on the back of the center consol/arm rest. Does anyone have it?

Complete diagram for rewiring 1999 Mercury Mountaineer Audio system with: 8" Subwoofer, 6 disc CD Changer and CD Tape AM FM radio head unit

Help will be greatly appreciated.