New Head Unit For '02 Mustang With Mach 460

I purchased a new headunit to install into my '02 Mustang GT. It currently has a factory Mach 460 system in it right now. I purchased VR3 VRCD400-SDU from Wal-Mart (<Mod Edit: Removed link to competitor. Thanks.>). I've read plenty of good reviews about that headunit, and I'm somewhat short on cash at the moment, so I picked that up a few days ago. I also purchased the Metra 70-5519 wiring harness (http://www.metraonline.com/products.aspx?s=70-5519)<Mod Edit: Linked to Manufacturer's site. Please link to Crutchfield's Item Page or manufacturer's website. Thanks.>to ease installation. As for the actual wiring part...I've come to a pause until I get some further help....

 

Here is the wiring specs for the VR3 headunit:

Left Front Speaker (+) : Green
Left Front Speaker (-) : Green/White
Right Front Speaker (+) : Grey
Right Front Speaker (-) : Grey/White
Left Rear Speaker (+): Brown
Left Rear Speaker (-): Brown/White
Right Rear Speaker (+): Blue
Right Rear Speaker (-): Blue/White
Ground: Black
Car Battery; 12 Volts Constant: Yellow
Ignition Switch: Red
Amplifier Remote or Power Antenna: Orange
Dashboard Light Dimmer Switch: White

Total: 13 Wires

 

Here is the diagram that was in the instruction booklet: http://img376.imageshack.us/img376/8186/vr3wiringri0.jpg

 

Here's the wiring specs for the Metra 70-5519 wiring harness:

Left Front Speaker (+) : White
Left Front Speaker (-) : White/Black
Right Front Speaker (+) : Grey
Right Front Speaker (-) : Grey/Black
Left Rear Speaker (+): Green
Left Rear Speaker (-): Green/Black
Right Rear Speaker (+): Purple
Right Rear Speaker (-): Purple/White
Chassis Ground: Black
Aplifier Ground: Black/White
Car Battery; 12 Volts Constant: Yellow
Ignition Switch: Red
Illumination/Dash Light: Orange
Dimmer Ground: Orange/Black

Total: 14 Wires

 

I'm having trouble figuring out what some of the wires on each wiring harness will connect to....The following is what I currently have figured out:

All four speakers (+ & -)
Car Battery; 12 Volts Constant
Ignition Switch


From the VR3 headunit's wiring adapter, I still have the following disconnected:

Ground: Black
Amplifier Remote or Power Antenna: Orange
Dashboard Light Dimmer Switch: White

 
From the Metra wiring harness, I still have the following disocnnected:

Chassis Ground: Black
Aplifier Ground: Black/White
Illumination/Dash Light: Orange
Dimmer Ground: Orange/Black

Any help with how I should connect these remaining wires would be very helpful. My final question is about the second harness that comes with the Metra 70-5519 (the one with the two RCA cables). To what do I connect the two Amplifier Ground and the two Amp Turn-On Wires to?

I'm not 100% sure on the grounds, but I think I'm right - say 97% sure.

You almost got it!

From the VR3 headunit's wiring adapter, I still have the following disconnected:

Ground: Black < to Chassis Ground Black Wire on Metra Harness >
Amplifier Remote or Power Antenna: Orange <to both blue/white wires (2) on Metra sub-harness (with RCA's)>
Dashboard Light Dimmer Switch: White <to orange wire on Metra Harness>

 
From the Metra wiring harness, I still have the following disocnnected:

Chassis Ground: Black <to Black on VR3 Harness>
Aplifier Ground: Black/White <to Amplifier Ground wires (2) on Metra sub-harness (with RCA's)>
Illumination/Dash Light: Orange <to white VR3 Harness wire>
Dimmer Ground: Orange/Black <cap off and leave unconnected>

Any help with how I should connect these remaining wires would be very helpful. My final question is about the second harness that comes with the Metra 70-5519 (the one with the two RCA cables). To what do I connect the two Amplifier Ground and the two Amp Turn-On Wires to?

Covered above - I guess you figured out that the RCA's go to the subwoofer outputs on the VR3.  The Metra instructions are here.

(If you really want to do it right you could use 4 Y-adapters so you are feeding both channels to both RCA's, but you probably wont need to.)

HTH!

So nothing will go into the regular RCA Line Out on the back of the VR3 headunit? Also, could you tell me how I would go about connecting the 4 Y-adapters? As you said, I probably won't need to, but just in case I do, I'd like to know how to do it beforehand.

Thank you so much for your help.

StartHere:

So nothing will go into the regular RCA Line Out on the back of the VR3 headunit?

Correct - unless you add an amp for your main speakers down the line, but you probably would need to upgrade your speakers if you did that.

I did forget to mention that you will need a 5V regulator from Radio Shack or you will get a popping sound through the subs when the amps turn on.  Info on that is here, and a previous thread mentioned you could use a PC floppy drive power (or probably CD-ROM audio cable) to connect it if you don't want to solder. 

Also, could you tell me how I would go about connecting the 4 Y-adapters? As you said, I probably won't need to, but just in case I do, I'd like to know how to do it beforehand.

Sure - for reference, here is a detailed thread on the Mach 460, here is CF's info on the Metra Harness Adapter (slightly different adapter), and here is the thread where I talk about the Y-adapters.

Just so you understand what is going one, Metra feeds the Red (RIGHT channel) HU subwoofer output to both woofers (rear 6x8's) and the White (LEFT channel) HU subwoofers output to the subwoofers (front 8").  While this sounds like it would be a terrible idea, keep in mind that bass is omnidirectional, and I believe Ford also does this from the factory, so if you didn't notice it with the stock deck, you probably won't now.  Also, keep in mind all those Y-adapters add a slight risk or added noise in the system, so unless is really bothers you, I probably wouldn't go to the added trouble.

HTH! 

Thank you so much for your help. I will be connecting it this afternoon. I won't solder the wires until I'm sure that it's working correctly. I will post back with my results.

Awesome. I tested the connections this morning, and they were working perfectly. There was a small pop when the sub amps turned on. It's not too noticeable, but I'm going to buy the regulator because that pop will probably get annoying after a while. Thank you so much for your help. I can't tell you how happy this makes me after getting nowhere from StangNet and AllFordMustangs.

Glad it's working!!!