Tip on installing a Aftermarket Navigation HU on a GS with Nakamichi
First off, use the information at your own risk. I’m not responsible if you screw up your car. I’m not an engineer, or a professional. I just do this as a hobby.
Secondly this is not meant to be a comprehensive DIY how to. Just some tips and info on what I did. Also I installed this in 2009, so it has been 3 years, but since there is not a lot of info for us folks with Nak system to aftermarket . . . . here is what I did.
My car is a 2000 GS300 with the Nakamichi system. I installed a Pioneer AVIC-D3 w/ Bluetooth in it. My subwoofer is not connected. I could probably figure it out, but never got around to it. Also the amp is in the trunk, not behind the glove box like the non-naks.
You will need the METRA Toyota harness (or any aftermarket 87+ toyota) to route to the speakers. Looks like this
So basically, you are going to bypass the amp in the rear. So instead of running new wires to the speakers in the door, you are going to take the Toyota harness plug it into the stock radio plugs. DO NOT CONNECT IT TO THE AFTERMARKET HEADUNIT YET.
You will only be using these Metra harnesses for speaker ONLY.
So the Front right +/-, Front left +/-, rear right +/- and rear left +/-. A total of 8 wires you LATER directly connect to your new HU harness. Write down the corresponding wire color. (ie – From the Metra harness, it should say which is FR+, FR-, RR+, RR- etc . . . plug it in, look at the corresponding stock wire color.
It should be
(on the small plug)
RR+ = Red
RL+ = Black
RL- = White
Now go to the trunk, under the right side of the floor, remove the cover and you will see the amp. There are 4 plugs on the left side of the amp. Unplug all 4 plugs. Tape up the grey and orange plug. You will not use those anymore.
SIDEBAR: This is the point of no return. You will be cutting wires off the white and green harness plugs. I left like 1.5 inches of wire when I cut it off the harness just incase I want to go back, to stock, but realistically, it would be a PITA.
The white plug is the input wires from the head unit. Those wire colors will correspond to the ones mentioned above.
On the green plug, this is going to the speakers, The color is as follows
FL+ = Pink
FL- = Purple
FR+ = Light Green
FR- = Blue
RR+ = Red
RR- = White
RL+ = Black
RL- = Yellow
So now you connect the colors from the white plug to the corresponding one on the green plug.
FL+ = Pink----FL + = Pink
FL- = Purple----FL- = Orange
FR+ = Light Green---FR+ = Light Green
FR- = Blue----FR- = Purple
RR+ = Red----RR+ = Red
RR- = White---RR- =Green
RL+ = Black----RL+ = Black
RL- = Yellow----RL- = White
(Updated thanks to Moneybagz)
Once connected, it should look something like this.
There should be 3 extra wires on the white plug that you will not use.
NOW the reason you did not connect the metra harness to the aftermarket headunit is so you can now test your connections. Take a double A battery and place the RR+ (Purple) on the positive end and the RR- (purple / Black stripe) on the negative end of the Metra harness, and listen for the speaker to crackle. That is how you know that the speaker is connected. Be careful not to blow your speakers.
Now to connect the other wires.
12v (ignition) = Grey
Constant (Battery) = Blue/yellow
Negative (Ground) = Brown (I actually did not use this one, but instead connected directly to the metal bracket in the side)
Illumination – Green wire on the orange plug
VSS – purple wire on blue plug under the driver side (see picture below)
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Great Write up I just finished this in my gs after searching through the forums for forever trying to find a good write up...I will have to add that the wiring had me a little confused at first so I will add this to help people in the future to match up the wires at the amp...Thanks OP
The reason I’m posting because I am currently not getting any power to my freshly installed aftermarket radio. I am attempting to run a AVIC 700BT Pioneer. Below is a breakdown of how I have my wires connected. All speakers are wired correctly I tested them using a double A battery, so I will leave those out of my explanation. I have reset my radio, checked my connections that they are secure, and checked the fuse in the back of the radio.
These wires on the left are from the orange stock car harness which I cut/connected to the radio harness wires on the right