JBL (factory) system wiring diagram...?

[SilverSHO]

I probably oughtta look in my EVTM, but if it's not there, does anyone have a wiring diagram for the factory JBL premium audio system? My SHO has an aftermarket head unit that was installed (sort of) by the previous owner, and pulling it out, it looks like Edward Scissorhands did the wiring. The door speakers work, but the rear speakers don't.

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Nick
Lt. Titanium 90 135k
Coneless, ACCEL 8.8 stainless steel wires,
SHO Shop torque limiters, Cherry Bomb Turbo II mufflers
AIM: loudog6491