unusual wiring harness, 96 explorer w/jbl

I'm trying to finish up an install in a 1996 Ford Explorer Limited Edition with the JBL stereo.  I've gotten both the Metra and Scoche harnesses, and neither of them mate up to what I'm assuming is the speaker connector.  The power connector from the Metra kit does match the one in the dash, although some of the wiring seems to be different.  Does anyone have the color codes for the speaker wire (the second connector has 8 wires, 5 in one row and 3 in the other)?  Also, I'm assuming there is a turn on wire for the factory amp (I'm trying to use the factory amps and just install a line level converter from the new stereo to the existing wiring).  Any idea on it's color/location?  Thanks!

I'm pretty sure I'm familair with that car. Check to see if in the radio cavity, if there is a group of wires running straight up and down in the back of the cavity a little to the left. I'm pretty sure you can find speaker wires in there and bypass the amp. Any reason you want to use the factory amp. Your radio is probably pushing more than your fact amp.