How to Modify the Stock Fiero Radio for MP3 Players, With Pics. (Page 1/7)
fierohoho MAY 10, 11:23 AM
After seeing this post...

http://www.fiero.nl/forum/Forum6/HTML/041428.html

...where Jax184 mentioned he had modified his stock GM radio so an MP3 player could be plugged into it to play over the car speakers without one of those FM Transmitters we traded a few PM's and this thread is going to be me posting pics and him walking me/us through this modification.

I will first post some pics of the stock radio I took out of my 84SE.

The front of the radio.


The passenger side.


The rear.


The drivers side where I believe the Amp board is located that we need to access.

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Where will the road take you today?

Some helpful links I've done
How to remove inner door panels, with pics.
How to remove outer door panels, with pics.
How to make rear coil-overs using factory struts, with pics.
How to remove rear bearing hubs, with pics.

fierohoho MAY 10, 11:31 AM
The top.


The top removed, mine had 2 screws holding it on.


The Amp board side.


Removing the front face I pulled off the volume and tuning knobs and the little knobs on the equalizer.
fierohoho MAY 10, 11:33 AM
You'll have to remove the bottom plate as well, three screws I think, it has a couple tabs that hook into the
radio's face on the bottom edge.


Looking up into the bottom of the passenger side.


The front with the face off.


When taking the face off there are 4 little tabs, 2 on each end, you have to carefully pop loose.
fierohoho MAY 10, 11:38 AM
This is the 1/8" stereo bypass jack I found at an electronics surpluss store.


When you plug a stereo headphone jack into it it will stop the signal from going
through it and allow a new signal to go through it in its place.

This allows the MP3 player to use the Amp from the radio to send a clean signal to the speakers.

OK, now it's Jax184's turn, what do I need to do or take apart now?

Jax184, as I have the equilizer controls on the front of the radio I am limited as to where I can put the stereo jack,
I'm OK with putting it at the back as there seems to be room there or maybe I'll even do a remote mount.

[This message has been edited by fierohoho (edited 05-10-2006).]

Fiero STS MAY 10, 11:47 AM
Cool write up so far ( I like the pictures). I will try this with one of the newer Pontiac radios that I have. This is also a good time to rplace any burnt out bulbs, you can get the grain of wheat bulbs at Radio Shack

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Signature courtesy of MinnGreen.

[This message has been edited by Fiero STS (edited 05-10-2006).]

tesmith66 MAY 10, 11:55 AM
I'm watching...

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1986 SE 350 V8

Ultimate MAY 10, 12:01 PM
wow.. good topic to write on. Looking forward to seeing how it goes.
fierohoho MAY 10, 08:27 PM
OK, did a few more pics.

Here's what will hook the MP3 player up to the radio.


Here's a couple with the Amp board taken loose.





What should we be looking at Jax184 as the left and right wires to tap into?
Jax184 MAY 10, 11:21 PM
If you look at the amp board, you will see a series of white wires held into a strip with a piece of masking tape. Two of these wires carry the raw unamplified audio signal from the tuner/tape mechanism. Simply look to the tuner board, where they connect, and you will find an "L" (Left channel audio) and "R" (Right channel audio) written next to the wires you want.

Next you carefully unsolder these two wires from the amp board. Pull them from their tape backing, without mixing them up. These two wires will go to the headphone jack, so that they will be connected when nothing is plugged into the jack.

After that you need to solder in two short wires between the jack's output lines and the amp board.

But wait, I hear you ask, how do I know which pin is left and which right on the jack? Well, if you have a volt meter, it's pretty simple to figure out.
Set your volt meter to ohms (to show when a connection is made) and plug that short length of audio cable into the socket. Now touch one line of the volt meter to the very tip of your audio cable's connector, and find the pin that shows power on the jack.
Ta dah! You just found the left channel, and what gets connected to the "L" solder point on the amp board. Repeat the process with the middle part of the audio cable's connector.

Once you know which pin is Left and Right on the jack, you'll need to also find out which pin is Left and Right on the jack's passthrough. So unplug the audio wire and, using your volt meter again, find which pins show a connection with the L and R pins you already found. These are where you attach the two wires from the tuner board.

Alright, almost done now.

You might notice about now that there's one pin on the jack that we havent used for anything. This is the ground pin, and must be connected to the stereo's ground somehow. There's many places where this can be done, as it's all a common ground. I'll leave it up to you to decide where to solder the ground pin to, but I simply soldered it to where a nearby screw went into the metal frame.

After this you need only mount the jack. On the radios that lack an equilizer, there is a perfect gap between the display and the volume control.
You can see where http://www.jax184.com/pictures/car/IMGP2917.jpg
(Yes, that's my radio)
To mount here, you only need to find the gap in the metal framework, and drill a jack-sized hole infront of it. Then glue the jack to the framework.

Radios WITH the equilizer will need to find another place. I've not done this to one myself, but it looks like there may be a spot directly above the LOUD button.

Note that having the jack on the back of the radio would be a bad idea. You'd need to dig around behind your radio surround every time you wanted to switch between using the radio and whatever you have plugged in. Not fun.

Now you just need to reassemble the panels and put the radio back in. Congratulations, you've just brought your Fiero's stereo into the 21st century.

If any of you arnt comfortable with performing this modification, but would like it done, I'd be happy to do it for you. Simply mail me your radio with return postage and a few bucks to cover the work, and I'll have it shipped back out in a few days. Email me if you're interested.
fierohoho MAY 11, 04:17 AM
Thanks for the response Jax184, I believe this pic shows the white wires held into a strip with masking tape.



When I get some time I'll pull the tape and try to get some pics of the next step
along with wiring up the jack.