Adding an input to my car stereo

[Syntax42]

I have a fairly old Honda stereo that only has a tape player and a proprietary auxiliary input connector. I could not find pin information for the aux input connector and I assume it has circuitry to detect a proper load before allowing the stereo to be switched to aux input mode. Aux input adapters cost over $50. I'm looking to do something cheaper so I can hook my MP3 player or cell phone up to the stereo. I have searched the internet for several hours and could not find a solution for my specific stereo model.

I have identified two possible options.

I could solder my input directly to the amplifier chip. I found a spec sheet for it here. The problem with that is the chip is designed for 4-channel output and unless I want to short two pairs of channels together, I won't be able to solder to it. I also don't know how the pins are numbered.

My other thought was to solder to the left and right channel outputs of the FM demodulation section of the circuitry. The demodulation section is standing vertically and shielded. The left and right channel pins are labeled L and R on the PCB. I tested them using my cell phone to play some music and touched the wire to the L and R pins. I heard the sound, but it had a lot of static. The antenna was not plugged in to the radio and it was not tuned into a station. If I use this method, can I expect the static to go away with a solid electrical connection, or will the antenna's static persist because I am not tuned into a station? This radio is old enough to play static even when there is no signal.

I want to get some good opinions on this before I take the time to solder connections. It is not a friendly circuit to work on and may be difficult to avoid causing an unwanted solder bridge.

 

[cr0sh]

Do you have any more information on the stereo (model number of unit, model of car, year of car)? Were you unable to find anything searching the internet for "honda stereo auxilary input pinout" or similar terms?

 

[Syntax42]

I spent hours searching last night. I used many terms and combinations that I thought would lead me to the answer I was seeking, but my model of radio must be rare, complex, or the information is not widely shared.

My $100 Rampage unit was stolen from my car and I replaced it with a radio that looks stock because it has the Honda name on the front and it doesn't play CDs. The part number on it is 39100-s84-a020-m1. I did try searching for that.

I forgot to mention that I tried to use one of those cassette tape adapters that has the cord on it. My radio just kept ejecting it. It does play a regular tape though.

I'm really thinking my second option would be the best one to try. I just don't want to try it if someone knowledgeable says I can't get rid of the static that way.

 

[cr0sh]

I forgot to mention that I tried to use one of those cassette tape adapters that has the cord on it. My radio just kept ejecting it. It does play a regular tape though.

If you can figure out why the player is ejecting it (or mod it so it won't), it might be a good solution (not the best, obviously). You could then leave the tape in place, then route the cord out the back and to a convenient place for your player (the thing I hate about those adapters is all the cords everywhere around the dashboard).

 

[cr0sh]

Can you get a picture of the connector? Or - is this an adaptor that would work for you:

HON98-AUX 1998-2005 Honda Auxiliary Input Converter

BTW - Here are some links (you may have found these already - but I am posting them in case they help):

Pinout For 14 Pin Connector On Stock HU - Honda Civic Forum
Pinout for Aux Input on LX - 8th Generation Honda Civic Forum
Need help identifying a connector on a 2000 Honda Civic radio - diyAudio
Miata Audio Pinouts
Adding aux input on OEM Integra Radio. - Honda-Tech
Need Pinout details for the 14 pin CD Changer connector - Honda Pilot - Honda Pilot Forums
AUX input not recognizing HONAUX4 adapter - Drive Accord Honda Forums
How to connect MP3 player to factory radio??? - Honda Car Forum - Accord Parts Civic Tuning Acura Racing

It seems like if its the 14-pin adaptor, it may be more difficult to work around; but others have done it (ie - those who make the adaptors, at least) - so there may be some hope; the 6-pin DIN adaptor (PIE adaptor?) seems easier to figure out, if that's the one...

???

 

[Syntax42]

My previous post hasn't been approved by a mod yet, but here's an update.

That connector is the right one. I don't want to spend $50 on the 14-pin adapter if I can make this work without one. The tape adapter is also something I want to avoid using because they don't seem to be as reliable as they should be.

I looked at the "Need help identifying..." thread and found schematics for a similar radio. The pinouts matched with my radio's labeling on the PCB. Even with that knowledge, I was unable to activate the cd/aux input mode. I'm guessing those aux converters have some sort of digital signal to send to the radio unit.

I tried riding into the radio's input signal again. This time, I had a solid electrical connection. I was still able to hear the static or station playing in the background. The only way I can make that work is if I transmit my own FM signal to prevent local stations from interfering with my music. That involves spending more money, though.

The last thing I see that I can try that doesn't involve adding components to this is the NAV inputs on those schematics. I'm guessing those are inputs for a GPS system, but my radio might not support them because it is a different model.


Edit: My dad found a FM cell phone sound transmitter thingy. He said it didn't work well, so I "extended" the antenna directly to my radio antenna input. It works, but I wish I could have done it directly through the radio.

 

[audioguru]

An old radio that has a "tape player" should be buried.
My car radio is pretty old (5 years old) and plays CDs and MP3s.