Putting aftermarket head unit in my sons 2004 Ranger. It has a factory amp and single 8” woofer.

on the aftermarket that clips to the factory harness that runs to the amp, there is one wire I can’t figure out. The wiring diagram shows it going to "fused ignition". The factory wire leading to the factory harness is uninsulatwd stranded wire and shows an inline fuse.

The marching pin on the aftermarket harness is a black and white wire, which the package lists as amp ground. However, this pin is shown as fused ignition when clipped into the factory head unit. I will attach a picture of the schematic and harnesses to better explain.

move get every other connection figured out except this one.

If anyone can help me with this I would really appreciate it.

 

There were 3 different audio system for the 2004 Rangers, seen here: https://www.therangerstation.com/tec...ring-diagrams/

All 3 will have a wire from fuse 21, you DO NOT hook this wire up to any 3rd part unit, tape it off, it only has 12volt when cranking engine over and it MUTED the Ford Radio
People have hooked this up to another 12v wire and engine started cranking with key on, lol, and stayed cranking after engine started, so DO NOT use this wire, but you need fuse 21 so don't pull it out
So heads up

The "fused ignition" wire is actually mislabelled in a few drawings, its actually just a shield/ground wire for the "line level" signals going to the amplifier, which is usually not needed

 

okay…. I’ll have to go make sure the wire you’re talking about doesn’t have a pin that connected to anything on the factory harness plug. I’m pretty sure I have the Audiophile sound system, and I see the wire you mean in the diagram. I would hope that you can purchase a harness adapter and not have to worry about that but I’ll be sure to double check.


as far as my mystery wire,…

So do I just not connect it to anything or do I connect it to ground? If ground I’m assuming it can be the ground from the other, common wire harness that is probably just the radio housing…

thanks again for your help.

 

Leave it unconnected, its a Shield wire
A shield wire is often used on wires that use frequencies for signals not just voltage, so line level audio signals are just that, you may have seen metal foil around a wire harness with 2 to 10 wires inside the foil, the foil is a shield
Only one end of a shield wire/foil is grounded, not both, the point is to "shield" the wires inside from outside RF(radio frequency) interference, in vehicles the spark system and alternators can generate RF, also local CB and emergency vehicle radio traffic, however inside the Metal vehicle and in and under the dash the RF interference should be negligible, but engineers like to use them because they can, and there is no downside to adding a shield wire
But if you are not using the original harness for the wiring between head unit and amp then there is no hook up for it, and not needed in any case

 

YESSS!!!!!

Thats why I registered and posted a question! Cause I knew somebody who knows their **** would help me out!

Thanks man! I had kind of suspected what you just said, but didn’t know if it needed connected or not and now I know.

I do have another quick question I bet you would know the answer to though….

The factory amp has only one channel of sound going to it. You can see in the diagram it’s just two signal wires + and - like you mentioned.
However the harness has two RCA cables that will plug into the new stereo rear speaker outputs. What I did was just splice the two rca cables (left and right) together so that it’s getting both channels and not just sending only the left or only the right signal to the factory amp and sub.

That should be fine, right? I figured it probably won’t make any difference but did it anyway.
It’s all just mocked up for now cause his sub won’t be here till later this week.

He is 17 and just HAD to have a subwoofer in his truck. Haha.
"I don’t have any idea where he gets that from!"
………I say with a sideways glance and memories of my father shaking his head at the 2 15” subwoofers that took up the entire extended cab of my truck when I was his age and were just obnoxious……hahahaha

He came home from school with a big assed box with two 12’s and I said no….. Let’s start with one 10” and see what you think. Haha.

So yeah. We went ahead and hooked it all up without it and it worked just fine. But it would have bothered me until I knew for sure. Thanks for your help.

 

Not sure you are reading the diagrams correctly or what audio system was in the Ranger originally

There are 8 speakers wires, 4 pairs of +/- for the 4 speakers
Then one pair +/- for the one subwoofer, this is a combined left and right channel with a low pass filter, so just has a lower bass frequencies on the wires

The audiophile system has the head unit powering the 4 speakers(so built in amp) and then a line level subwoofer output, +/-, to a separate amp just for the one subwoofer

Premium audio system uses a head unit with no built in amplifier, and runs 4 pairs of line level speaker outputs to a separate amplifier, and also a line level subwoofer +/- to same amplifier for two subwoofers

So no, you should not be splicing together left and right channel RCA cables(line level) to get a Mono signal, you can build a Mono "pad" with 1 or 2 resistors to do that but no reason in the world to do that, channel combining is done in the head unit or amplifier for the subwoofer

Subwoofers just get a mono signal in any vehicle system, as they are one speaker, even if you have 2 subwoofers, in a vehicle there is not enough speaker separation distance to have a left and right subwoofer channel
In home theater setups you can do that, i.e. 7.2 or 9.2, the .2 means there is a left and right subwoofer channel, but need at least 7ft distance between the 2 for any benefit of a left or right difference

 

I really appreciate you taking the time to talk about this with me.

Let me explain what I’ve got.

I’ve got the audiophile system. It has a factory amp and 8” subwoofer. I understand what you’re saying about the factory stereo output signal to the amplifier being filtered and how it’s wired and designed from factory.

Im replacing the head unit, adding an amplifier and 10” subwoofer. Maybe a pair, but for now just 1.

I got him a new Pioneer head unit. . He wants Bluetooth. I get it.

Usually, people probably just add an Amplifier and subwoofer. Originally, we were just going to do that and not bother with the existing factory amp and sub. Just leave it unconnected. But I decided get the other harness adapter and to try to utilize the factory amp and sub for mid range.

The new head unit has the regular speaker outputs like normal, and three RCA outputs. They are:

L&R Front on standard or high range on network

L&R Rear on standard or mid range on network

L&R Subwoofer

I planned to use the subwoofer outputs for the new amp and 10” subwoofer.
Since his truck has a factory amplifier and 8” subwoofer, I figured it would be better to have it run from the Rear Speaker outputs/mid range outputs instead of the subwoofer outs since that can be a mid range output in network mode.
Im not an audio guy at all. My simple thinking was throw the midrange sound at the mid size speaker, right? It’s not a very powerful amp, and I thought who knows, it might sound great.

We have it hooked up like this now and it sounds great. When his 10” gets installed I think he will have a better sounding stereo than I’ve ever had.

So If I shouldn’t have spliced both channels, which channel do I use. I think sometimes with subwoofers with mono input you just use the right channel, but that is for sub signals like you said that are filtered and combined in the head unit.
I want to hear how it sounds running mid range signal to the 8”.

Maybe I’m trying to put a square peg in a round hole by doing this, but I want to have the little sub run midrange if that’s even possible and even thought it’s not really designed for that. Call it an experiment.

What are your thoughts?

Can I leave it like it is? Sometimes music has signals from turn left or the right separately and I wanted to make sure the speaker was getting all of the music if that makes sense. If I need to change it how should it be? Can I make a mono pad like you mentioned? Will that work for what I’m trying to do? What exactly is a mono pad and how does it work? I’m curious about that.

Again, I thank you for your help. It sounds like you know what you’re talking about so if you’ve got the time and inclination, break it down for me.

 

You won't use the line level high and mid ranges
Just run the RCAs to the amp and subwoofer you are going to use now
If you want to add another subwoofer then just daisy chain the RCAs from one amp to the next but make sure to ground the two amplifiers and head unit together

8" speakers would be unkind to mid-range frequencies in this application, you want 4" to 6" mid-range speakers in vehicles, and most home systems

The 4 current Ranger speakers should be 6" mids with 3/4" to 1" tweeters, with a built in cross-over on the back of each speaker, cross-overs send highs to tweeter and mids to 6"

The line level high, mid and low are if you were going to run separate tweeters, separate mids and separate subwoofer speakers, and you would need a 9 channel amplifier or 10 channel if 2 subwoofers

 

well you’re no fun……

I’m kidding of course.

So the question I had was, will it hurt anything the way I’ve got it. And I’m gonna assume if there was any sort of major issue, other than it’s not the right type speaker for that and won’t sound good, you would have mentioned it.

If it won’t blow up or make my head fall off I’ll probably leave it like it is unless it’s just awful sounding.

AND I learned to recognize the symbol for a shield wire on a schematic and how they are used… and if I ever see that again…

Im gonna think of you, RonD.

RonD the knowledge tree!!

How cool is that? Not all hero’s wear capes buddy…..

 

As long as the line level low and mid use different channels/amps then no issues, you do not want to recombine them

6" speaker will do mid just fine
8" speakers with mid signal, along with the 6" speakers will make the mid-range "muddy" so not a clear sound, may effect subwoofer as well depending on how good the low pass filter is, or what you set it at