JohnsonOffroad
Member
Hello Everyone!
I thought I would share my findings in case anyone else wants to use this information.
I have a 1998 Expedition with the Mach Audio system. I have installed a Pioneer FH-X731BT (2-din) head unit as the Expedition was missing the radio when I bought it. I have kept the original wiring and amps however the rear amp was not working. I found that it was shorted out (terribly corroded from moisture exposure). Using a multi-meter I was able to determine what the five wires are that feed the stock amp so that I could wire in an aftermarket amp.
The power wires in the grey connector:
Green/purple: 12v power
Black: ground
The black and red connector:
Red/black: ground
Black/orange: 5v pre-amp
Green/Black?: 12v remote turn on
I cut the connectors off the wires and added additional wire for length. The +5v pre-amp (black/orange) and ground (red/black) I wired into an RCA plug for the low-line inputs of the new amp. The other wires I tinned the ends as they are connected to screw terminals.
I hooked up and inexpensive Boss amplifier (R1100M) and it works!
Now with all that stated, I admit that I am having some sound quality issues that I am going to be troubleshooting. Basically, the subwoofer is doing a lot of buzzing. The sub could be blown, the audio signal could be bad or poor, or my wiring job could just suck. If I find out the cause I will make sure to update this thread.
One last thing, hook up that remote turn-on (blue or blue/white) if you decide to replace the stock head unit. The Premium/Mach amps wont turn on without it.
I thought I would share my findings in case anyone else wants to use this information.
I have a 1998 Expedition with the Mach Audio system. I have installed a Pioneer FH-X731BT (2-din) head unit as the Expedition was missing the radio when I bought it. I have kept the original wiring and amps however the rear amp was not working. I found that it was shorted out (terribly corroded from moisture exposure). Using a multi-meter I was able to determine what the five wires are that feed the stock amp so that I could wire in an aftermarket amp.
The power wires in the grey connector:
Green/purple: 12v power
Black: ground
The black and red connector:
Red/black: ground
Black/orange: 5v pre-amp
Green/Black?: 12v remote turn on
I cut the connectors off the wires and added additional wire for length. The +5v pre-amp (black/orange) and ground (red/black) I wired into an RCA plug for the low-line inputs of the new amp. The other wires I tinned the ends as they are connected to screw terminals.
I hooked up and inexpensive Boss amplifier (R1100M) and it works!
Now with all that stated, I admit that I am having some sound quality issues that I am going to be troubleshooting. Basically, the subwoofer is doing a lot of buzzing. The sub could be blown, the audio signal could be bad or poor, or my wiring job could just suck. If I find out the cause I will make sure to update this thread.
One last thing, hook up that remote turn-on (blue or blue/white) if you decide to replace the stock head unit. The Premium/Mach amps wont turn on without it.
