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-   -   How To: Aftermarket radio wiring with stock SVT sub and amp. (

MattZX3 01-23-2008 11:16 PM

How To: Aftermarket radio wiring with stock SVT sub and amp.
Hey, just wanted to post this up for all of you svt guys, helped out another member on here with this wiring.

If you want to replace the audio-pile with an aftermarket, but want to retain the stock sub, follow this wiring and you should be all set

When installing a deck in a 2003 Focus SVT I was able to integrate the factory sub amp using the extra 7 pin plug from behind the factory radio. the wiring in the plug is as follows:
white/red- amp turn on (6volts)
white/black- column control(resistance)
brown/yellow- column control (power)
white/black- pre amp output (+)
grey/black- pre amp output (-)

I used a 249 OHM resistor to drop the amp turn on (white/red)voltage so that the sub doesn't pop when the radio is turned on/off. Using a male RCA connector, you can wire into the low level factory input wiring (white/black,grey/black) so that it will accept the female sub output on the aftermarket radio.

Make sure that the new deck has an adjustable/low-pass sub out, or you will need an adjustable crossover. Good luck, and have fun!!

Step 1:
Cut the RCA cable in half and strip it like this: The white area is the positive and the other area is negative.

Step 2:
Cut two 1-foot (1 Red, 1 Black) of 16-gauge wire and connect it to the spliced RCA wires from Step 1. Red with positive and black with negative. Note that the RCA end will plug into the sub output from your receiver.

Step 3:
Cut another 1-foot of 16-gauge BLUE wire and connect it to the red and white wire. This wire is for the remote (turns your amp on and off with the ignition position).

Step 4:
Cut another 1-foot of 16-gauge RED wire and connect it to the black and white wire. This wire is for the positive sound input.

Step 5:
Cut another 1-foot of 16-gauge BLACK wire and connect it to the black and grey wire. This wire is for the negative sound input.

Step 6:
Now you would connect the Red & Black wires together from Step 2 to Step 4 & Step 5. (Which completes the sound inputs)

Step 7:
The BLUE wire from Step 3 needs to be connected to the remote switch wire from your deck (This color varies depending on your head unit model, consult your owner's manual). If you get a popping noise then you will need to install Resistor between the two to lesson the load.

Sonicbluezx3 01-30-2008 03:01 PM

Got any pictures?

MattZX3 01-30-2008 03:38 PM

i unfortunately do not...

i do believe another member or two have used this wiring, so hopefully they either have pics, or can pull the radio out to take some pics

pat247 02-26-2008 09:07 PM

Aftermarket radio wiring with stock SVT sub and amp.
After searching around for wiring info for the stock SVT sub and amp, and unable to find any usable info. I decided to make a small "how-to" for you guys.

Solder and shrink wrap wiring harness connections

Wrap wire loom around wire bundles (so it looks good)

Strip single RCA cable and twist core wire and shield wire like shown.
Solder "male" spade connector to blue/white wire.

Solder Blue/White wire to the White/Red wire.
Solder RCA core wire to the White/Black (+) wire.
Solder RCA Shield (negative) wire to the Grey/Black (-) wire.

Shrink wrap connections

Will update with more pics of the sub wiring harness later.

If anyone has any questions I will answer them as best I can.

MattZX3 02-27-2008 12:04 AM

look about two or three thread up and i posted about it, im actually going to merge those threads, because you have pictures..

when i did the install, i didnt take any pics.. so ill merge the two threads together

MattZX3 02-27-2008 12:10 AM

threads merged

focusguy87 03-02-2008 06:47 PM

this is great good jobs guys!

lildudeinacar 04-03-2008 05:18 PM

Just my luck, now i gotta buy a stuiped crossover..... and now i got to hope and pray that i dont screw up this simple wire job.

FOCUSSTDRIVER 04-25-2008 09:31 AM

um will this work on 2007 focus?

WUGcatsvt 04-25-2008 07:38 PM


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