I've spend more than 5 hours scouring the internet and G35 driver trying to find a diagram of the Bose amp for my car, or even a similar year, but links were missing, or there wasn't enough information. So, I made one! In conjunction with the service manual and using a multi-meter on the harnesses, here what I came up with. There are 2 harnesses going to the Bose amp.
Grey Connector: holds the power, ground, and speaker output to the rear deck woofers.
<a href="http://s30.photobucket.com/user/pidrummer/media/Grey%20Connector.jpg.html" target="_blank"><img src="http://i30.photobucket.com/albums/c350/pidrummer/Grey%20Connector.jpg" border="0" alt=" photo Grey Connector.jpg"/></a>
Blue Connector: holds speaker output to cabin speakers (top) and pre-amp inputs (bottom):
<a href="http://s30.photobucket.com/user/pidrummer/media/Blue-Connector.jpg.html" target="_blank"><img src="http://i30.photobucket.com/albums/c350/pidrummer/Blue-Connector.jpg" border="0" alt="Blue Connector photo Blue-Connector.jpg"/></a>
Note that the tweeters in the front of the car share one output from the Bose amp.
Note that the rear deck woofers take their pre-amp signal from the rear speaker inputs.
Here is the service manual I used as a resource while making this:
http://www.nicoclub.com/FSM/G35/Coupe/2005/av.pdf

Later I plan on adding a video on my audio setup.

 

Great write up!

So when you say front right and front left is that looking at the head unit from drivers seat? Just want to make sure I get this right.

So if I tap in dorectly to these wires (ie: gray + yellow, green + red) from a 4 channel amp then it should work? Thanks!

 

Just go by the colors, not position, and you're fine, and yes, those are the correct colors to attach the speaker-level outputs from your new amp to.

 

These connectors are on the end that plugs into the Bose amp that's in the trunk. Wrathernaut says the colors should match at the head unit. He's pretty well respected around here, so I'd take his word for it.

If you are wiring an additional amp, I'd recommend that you tap into the connectors from the trunk since that's likely where you're going to have the new amp. Note that you can tap either unpowered audio signal if you want to just feed the amp signal, or tap the speaker outputs if it can take speaker level power input.

 

Thanks for the reply. Yes Wrathernaut has helped me out a ton!

I am eliminating the BOSE amp completely and putting in a new head unit and speakers in the front doors and the rear deck with 6x9's. I finally got the head unit working but wasnt sure if I should run all new wires for the speakers or tap into the existing ones. With this forum help, I have decided to just tap into the connectors off the BOSE amp for signal. I have removed the amp from the vehicle and cut the connector off. I am going to test fir everything before I run the wires under carpet and make sure it all works. I am not going to be using the 6.5 inch speakers next to the seats. I am hoping it all works out!

 

They're different colors at the headunit, but those are the amp connectors.

 

If I were going to bypass the Bose amp all together, I would just use the line level signal from the harness that plugs into the Bose amp as your new amp input, and use the powered speaker wires that are on the harness as well. That way you avoid running a bunch of new wire. You'll even have the remote wire coming off the Bose amp wiring harness to make it even easier.
The only time I personally would run all new wire is if you plan putting a significantly larger amount of power to the speakers. That's when you'll wanna get larger gauge speaker wire.

One thing to keep in mind, if you've already gone through the trouble of adding a aftermarket head unit, I might just skip trying to use the cars built in wiring harness all together and run everything as needed like you would for a car that doesn't already have an amp in the trunk. Good luck!

 

Yes I have already installed the aftermarket head unit. I plan on putting about 75 watts to each speaker and figure the stock wiring should suffice. I was advised by Wrath to run new RCA cables and remote wire from the head unit. I have a bunch of wires to run to the back (reverse camera, RCA, remote, bass controller, etc.) so I figured I should just run new lines for RCA and remote to be safe. I am still not totally sold on using the existing speaker wiring running from the BOSE amp but I figured I would test run everything before running it under carpet and see what I think. I don't really want to run new speaker wire because I don't want to get into putting silicone into the door jams and such. Thanks for replies! I appreciate the help.

 

The line level signal going to the bose amp is unshielded small-gauge wires. The factory setup relies on the headunit and amp using a differential-balanced signal to reject noise. If you use those wires as your inputs with an aftermarket headunit and/or amp, any induced noise is going to be amplified along with the audio signal, and is going to be a problem. If you're using shielded RCAs, you should be fine with that passive noise reduction. After the amplifier, you're running a high-level signal, so any noise induced in the unshielded wires is not amplified, and should be insignificant - so using factory wiring through the car back to the speakers is fine.

When installing a new amp in the trunk, you're running new wire to the trunk for power anyway, so most of the trim is removed anyway. Loosening the center armrest console enough to run a few pairs of shielded wires RCAs through it is a minor addition to the total work involved in the project.

 

Hope I responding right !! just joined!!!, hello my tweeters is not playing??? but all the otheres work!?