2004 Ford Mustang Mach 1 With Mach 460

i am trying to install an aftermarket head unit in this vehicle. everything is working fine except just no bass out of the factory speakers. i have contacted several wiring companies and they are of no help. does any body have a wiring diagram for the spare wiring plug that factory radio uses to turn on the remote factory amplifier ?

I have the same problem.  I'm actually just removing the factory amps now and putting aftermarket ones and rewiring the car.  There is no harness for the '04's yet, and somoene one here was doing it and never posted the final result and hasn't replied to PM's.

You can find wiring diagarams and info here:

But I dont know how accurate it is for the '04s

The ampilifier harness, is the 8 pin harness on the back of the stock radio. To get the factory amp and subs to work again you need to hardwire a line output converter into the system.  Pins 1 and 2 are the the positive and negatative subwoofer leads, if it has a pair of subs then pins 5 and 6 are the seconds pair of leads. i forget which on is the amp turn on, but i think it is the grey wire. Use a LOC that has a low pass filter and adjustable gains on it to properly match it with the new H/U. I use a Soundgate LOC and they work pretty well for that application.

Jazzy

i have a line out converter that converts from 'speaker wire' to rca's (i guess high level to low level?), will this work or do you need a low level to high level converter?  and what about the remote turn on?  I read that it runs at 8 volt, not 12?

Thanks,

Chris

well in that system it is a low level input on the amp, but if you dont use an LOC that is adjustable you wont be able to level match the new h/u with the factory amp. THere might be something about it being a differential input and not a single ended input like the new h/u is, not sure on that though. The amp is actually a 5 volt turn on, you need to use a 570 ohm 1/4 watt resistor in line with the amp turn on lead also, or else you will get lots of distortion when you try turning the volume up on the new radio.

Jazzy