Need some help guys, I got the Avic-Z140BH as the appropriate suggested wiring harness,
XM tuner, backup camera, and dash kit. So I am trying to solder up the
wiring harness from the new unit to the wiring harness adapter and found
that in the manual it states you connect the right rear speaker wires
to the sub and don't connect the left rear speaker wires.... So this
means my rear speakers won't be hooked up...and instead my sub will.
How do I hook up my factory amp/sub and keep my factory speakers also?  I am installing in a 2003 Mercury Marauder which has a factory sub/amp in the trunk. So my total setup is 2 front door speakers, 2 rear deck speakers, a rear deck sub, and a rear deck amp. (sub and amp are all packed together).



The manual states "When a subwoofer is connected to this navigation
system instead of a rear speaker, change the rear output setting in the
initial setting. (Refer to the Operation Manual.) The subwoofer output
of this navigation system is monaural." Then a little below that, "When
using a subwoofer of 70W, be sure to connect with violet and
violet/black leads of this navigation system. Do not connect anything
with green and green/black leads."



The speaker colors are as follows:

Left Front - White & White/Black

Left Rear - Green & Green/Black

Right Front - Gray & Gray/Black

Right Rear - Violet & Violet/Black



Then if connecting sub Green & Green/Black not used. Violet &
Violet/Black connect to sub only. Therefore no rear speakers... Help?

I'm guessing the 'sub' that the manual is referring to is an aftermarket sub. If you have purchased a wiring harness for your vehicle, and you make all the straighforward color matched connections, everything should continue to function.

The wirig harness you have that will plug into your vehicle will most likely use the remote wire to power your factory amp, which will power your factory sub. The connections you make for the speakers will most likely feed input to your factory amp and thus provide sound to all of your speakers.

Unless you're installing any aftermarket items, you can probably disregard.