96 Mustang original radio AUX

Since I got a request on how to install AUX into a 96 mustang, here it goes.
Even though it might looks complicated, I can assure you that it is not. I do not have much experience in wiring and I managed it pretty easily, although it does require som basic wiring and soldering skills. The radio I have is the F6ZF-19B165-CA. You can find out which radio you have by looking at the side of the radio. That being said, this should work for every radio with a separate cd player, just that the wires might not be the same color and in the same place.
What you will need for this project is: A car with the proper radio, some wires, crimping tool, wire tester pen or a multimeter and probably the hardest part to find, a 3.5mm stereo female with a built in switch like the one below.
One thing I can recommend is to buy a haynes manual, for more detailed instruction on removing parts.
And as always when working with electrics in your car, disconnect the negative side of the battery.

With all that out of the way, let’s get going!
Firstly, remove the radio and the CD player from the car like in this video.

Now, behind the radio there should be two similar looking grey wires, one with 6 holes and one with 8 holes. It is the one with 6 pins that we are interested in, that wire sends the sound from the radio down to the CD player, which then, if there is no CD playing sends it back to the radio. and if there is a CD playing, it will just ignore the sound from the radio and send the CD sound back instead. After that the radio will amplify it and send it out to the speakers. This is what we’re going to use to our advantage. We are going to break the connection between the CD and the radio on the way back and if we choose, use the sound from our phone instead.
For simplicity, you can also remove the plastic which is held by 3 screws, see the picture below

Now, inside the grey wire there are 6 wires, each going to a specific pin in the raido/CD and we are going to identify which of those we are going to cut. if you have the same radio as I do, you should be able to skip this step, but if you don’t or for some reason, the wires are not the same color as in these pictures, you can do this. Remember to write down anything you do so you remember what you are doing.

Now you can cut about 5-10 cm of that grey wire open to reveal the wires inside. Do not CUT the wire, just open it so you can get to the wires inside.

There are two easy ways of doing this, one is to just cut the all the wires and use a multimeter and measure resistance between the proper pin and the wire, and when the resistance is something close to zero, you’ve found the right cable. If the resistance is 1, then just test the next wire.

The other way (you will need to connect your battery again for this method), which keeps the other wires pretty much intact, is to find a pin or something somewhere in the radio wires where there is voltage, even when the car is off and then connect that to the proper pin. Then connect your pen to a ground somewhere. After that you use teh pen to poke holes in the wires and if the pen lights up, you know you’ve got the right one.

The wires you need to identify are the following:

The next step is to cut these wires that you’ve identified. For those who has the same colors as me that would be:
in-L =purple
in-R = grey
Gnd = green
Now you can crimp the in-L and the in-R wires as if you are going to connect them to each other again.

Now let’s figure out what we are going to do with these wires. This is where it gets a little bit complicated. When looking at the AUX female that i bought I can see this:

I’ve marked out where the 5 pins are located on the backside. This switch works in a way that when there is no male plugged in, it takes the signals coming from the pins 3 and 4, and sends it through to pins 1 and 2. But when you plug a male in, in disconnects pins 3 and 4 and instead takes the signals from the male and sends it through. Combinng this with the design of the male, we can figure out where to connect our wires.

Since we have a stereo without microphone, we are going to use the middle one to figure out where to put our wires. As the diagram below shows, we need to connect:
1 to “in-L” going to the radio
2 to “in-R” going to the radio
3 - where 1 was connected to the CD
4 - where 2 was connected to the CD
Gnd - just connect this like in the image below

I sure do hope that I am not confusing anyone too much, but I think that this wiring diagram that I made look very professional (totally not made in paint in about a minute) will help atleast a bit.

Now it’s time to start thinking of where you want your AUX jack to be located in the vehicle. I put mine in the ashtray as I never use it and it would be a good place to store the cord.

Now, just cut up desired length of wires that are going to the jack from the connections that we made earlier. In total we need to draw 5 wires. I used an old telephone wire as it had 4 smaller wires in it and one extra for the ground. Now you can crimp the Gnd to the wire we cut before like in the image below. This is my result:
The wires going to the AUX jack in the image below are connected like this:
purple goes to 3
blue goes to 4
green goes to 2
white goes to 1

Finally, you just assemble everything back again, with the plastic we removed, the radio and the CD player. Now your AUX input should work just fine with the benefit of everything working just as before except for when you plug you phone in.

I hope you find this helpful and that you understood most of it. If you have any questions, please just ask me in the comments :)