I have a cool little CD player that I picked up at Goodwill for $3.00. I’ve been using it with a small FM transmitter, to listen to CDs in my car. There was always a bit of static, the CDs sounded flat and recently, a station in my area began transmitting on multiple frequencies, making the FM transmitter almost unusable.
I wanted to be able to plug my CD player directly into my car radio so I stopped into RadioShack and picked up a 1/8inch stereo plug to 1/8inch stereo plug patch cable and a 1/8 inch stereo jack.
I thought the hard part was going to be getting the radio out. Once I popped the trim off there were three screws to remove and the radio slid right out. I had to work the radio around the trim, but was able to get it out enough to remove the top and bottom covers.
Next, I had to find the signal from the radio frequency module to the amplifier portion (I actually did this step in he car and later took this photo on the work bench).
I plugged the cable that I purchased into the headphone jack of the CD player, connected a ground wire from the plug on the cable to the ground of the car and began trying the tip on various connections in the radio. I eventually found the left and right signals. I used my Black & Decker “Wizard” (like a Dremel) to cut the traces.
Next, I cut the circuit board on the face plate of the radio and drilled a hole for the jack. The jack was small enough to fit under the circuit board, but there weren’t any traces on the circuit board where the jack was going so I just got it out of the way.
I soldered wires so that when the patch cable was removed from the jack, the traces were reconnected. When the plug was inserted, the signal from the CD player was connected to the amp side.
When I put it back together and tested it, it didn’t work. The radio played when the patch cord was removed, but the CD wouldn’t play. After some trial and error I found out that radio cut out when the traces were cut. I had to short them together.
When the CD plays, it cuts out the radio, when it’s off, the radio plays and it sounds great. I almost can’t wait to go to work tomorrow, so I can listen to CDs on the way in.
This project was on a 99 Alero with the stock Delco radio.
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on Sep 30th, 2006 at 12:15 pm
Yo man, solid way to add a jack to your stereo.
I’ve just been reading through your blogs and your stuff is cool man, espically the ones about flutes! i repair guitars and do some wood work so that was pretty cool.
^^ Im suprised you don’t get that many comments though…
Anyway good work! I’ll check back every now and again!
on Sep 30th, 2006 at 12:17 pm
It would be nice if someone would do this for a 94 Olds cutlass supreme. Of course, I don’t want to rip it all the way apart this late in its life.
on Sep 30th, 2006 at 12:18 pm
You might find that a 94 Cutlass isn’t that different from a 99 Alero. Since it’s an Olds is should be a Delco radio. I don’t think the models changed that much from year to year.
on Sep 30th, 2006 at 12:19 pm
Gotta try this!!!!
I have 1999 Toyota Tercel and I’m an electronic newb, but… I guess all radio should have a “radio frequency module” and an “amplifier portion”.
So if I just find where I have to intercept this signal, I should be fine. Ain’t I?
on Sep 30th, 2006 at 12:20 pm
eric,
this is something i’ve wanted to do on my 96 jeep cherokee that i bought from my dad who only gets am/fm stereos on his cars.
Could you go into more detail about how you “found” the signal? I’m guessing you didn’t just hunt and peck for it, cause that might short something. Also, how/where did you connect the ground. I’m a newb like tapochedupied, but i’ve dreamed of doing for years when i used to borrow this car for long trips.
thanks! nice work!
on Sep 30th, 2006 at 12:21 pm
Actually, yes, it was just hunt and peck. The secret was to start with the wires that connect the silver box RF module.
Look at the pictures on Flickr…
on Sep 30th, 2006 at 12:21 pm
Thanks Eric!
It made sense once I looked at your flickr pics. I didn’t understand at first that you were only “hunting” on the RF module, that makes it a lot easier. My radio is different, but it shouldn’t be too hard to find the RF module.
on Dec 31st, 2006 at 1:55 pm
Great info! I’ve been trying something similar with a Sony boombox by tying into the tape head lines (inspiration: http://www.instructables.com/id/EO7O944OVBES9J44W3/). I took your suggestion to to use an audio jack, that works well, but I find that no matter what I use as a source, the music is very over-driven even with volume at it’s lowest and there is a hum even when the source is muted or paused.
Any thoughts on using the radio line versus the tape head? I’ve read that the tape head has to run through a pre-amp, maybe I could tie in after the preamp. Have you had any similar problems with the radio line?
on Jan 2nd, 2007 at 3:55 pm
Tape heads require a lot of amplification. If the cable from your MP3 player is long enough, it will pickup hum. I have a bit in the car, but only if I turn it all the way up. I’d complain if I spent lots of money on a car stereo, but it’s just stock, so thats par for course.
If you can find another place to cut into the audio path, that might work better for you. Rather than the tape head, you might be able to find where it goes from the radio to the amp. That might work better.
on Mar 7th, 2007 at 11:40 pm
First off: GREAT JOB, my hat is off to you sir.
Can you describe how starting the CD player cuts out the radio, and how when you turn the cd player off it re-connects the radio? (I think that is how you say it works).
I’m interested in doing this on my car too, but I didn’t quite understand how you wired it after you figured out where to wire it in.
Thanks!
- Dan
on Mar 20th, 2007 at 10:02 am
Dan:
Each stereo is different. On mine, what works was to just T into the signal that goes from the RF module into the AMP. If it is tuned to a radio station, I can still hear it just under the CD, so I tune it to static.
If I cut the signal from the RF, the AMP quits working. I think if I wired a COIL between the RF and the AMP then ran my signal to the AMP, it might work. To make it work without the CD, Id have to wire it so that removing the CD from the jack reconnected the RF to the AMP.
If I wire it that way, I’ll post information.
on Mar 21st, 2007 at 4:50 pm
Thanks for the clarification. This is a great mod!
Do you know why the RF signal loss cuts the amp?
What would a coil of wire do to help?
I just posted one on how to hide your fastTrak toll tag, check it out: http://www.bayareaprelude.com/forums/viewtopic.php?p=143201
Thanks again,
- Dan
on Jan 26th, 2009 at 3:37 pm
I did the same thing on the Delco radio in my 1993 Saturn SL. Except it didn’t have a silver RF module… the FM radio was a whole to itself!
on Jan 26th, 2009 at 3:37 pm
CORRECTION: the FM radio was a whole *BOARD* to itself! Sorry for the mistype.
on May 6th, 2009 at 4:38 pm
hi men iam a mexican kid i have a 1999 camaro i have a cd stereo . original that i got from my auncle but i wanna installa aux so i can plug in a mp3 player how can i find the cables were i should conect the autlet help me plizzz
on May 6th, 2009 at 4:39 pm
it has a factroi amp. too
so help me out.
on May 9th, 2009 at 11:48 am
Tony: can you upload a photo to Flickr or somewhere, so I can see the inside of your radio? In the article, I have pictures that show how I used my CD player and a ground wire to hunt-n-peck until I found the right connections.
on May 14th, 2009 at 5:21 pm
no i can give you my email
it is zk_edgar@hotmail.com
on May 22nd, 2009 at 1:33 pm
tony: maybe you can take some pictures, upload to flickr and send me a link so I can see your radio. Otherwise, take a look at the article. I really just tried out different connectors.
-eric