Alternative question - how do i line my mp3 player into my stereo?

[repenttokyo]

I cancelled my XM service today and I have been using my Zune with its FM transmitter as entertainment in my car. The trouble is, the FM transmitter is absolute garbage.

Second problem: tape player in my car is no good, so I can't use a tape adapter.

Is there any way I can hardwire an AUX input into my receiver? I really don't want to have to replace the head unit - I like the all stock look.

[Tiger]

I think you can use the CD changer wire to send sound in... Basically you need to figure out which two wires act like left and right channels line in. I think someone did this long ago. maybe you can search it on this forum.

[repenttokyo]

I'm looking at something like this as a possible option:

http://www.crutchfield.com/p_142FMMO...r.html?tp=1701

I've taken apart my Zune transmitter to see if I could add an extra length of wire to the internal antenna, but so far no luck as it's much more compact than the original.

[attack eagle]

those work, won't be as nice as a direct line in on the changer input.

[Rick L]

This works if you have BMW Alpine C33 or C43. I found this from another BMW forum and it's a great idea to add line-in into TAPE line. See below...


So you have a nice iPod / iPhone but you cannot connect it to your factory stereo system because it has no aux input.

I have the Harman Kardon system installed in my car with the 10 speakers and a CD changer in the back. I wanted to keep the CD changer so that ruled out most of the adapter boxes that replace the CD changer with a connection for an iPod/iPhone.

Here's what I have done. First, I read the following thread: http://www.r3vlimited.com/board/showthread.php?t=118781

The guy did a good job. I thought about the same idea but actually didn't know how simple it is going to be.

You will need:

- A BMW radio key (you can use a 2mm Alan key instead).
- Your radio CODE! Very important. Do not take the radio out without having the code.
- a 3.5mm stereo plug with a cable. A few $ at Radio Shack. I just used an old one I had lying around.
- A VOM (voltmeter) to check continuity.
- A soldering iron with a small tip and some solder.
- A cutter to cut the wire.
- Some tape.

First, you remove the radio from your car using the radio key. Then unplug the plugs at the back. The main plug is a bit tricky but follow the illustration on the top of it and it will come out.

Next, Remove the 2 screws holding the top cover. If you look at the back of the radio they will be the top left and top right ones. They pry the top cover off with a flathead screwdriver.

Inside the radio you will see the tape mechanism. It is held in place by 4 screws. Remove them and pull the tape mechanism out. It is sitting on the main board with a plug much like the one in the back of a hard drive but with only one row of pins.

On the back of the tape mechanism there is a PCB with electronic on it. At the top left of it there are connectors coming from the tape reading head. Look at the picture below.



Before you solder anything pass one side of the cable through the top cover like in the picture below. This is after the radio was already assembled together but you get the idea. Pass it towards the rear of the cover. Leave enough cable (I left about 2.5 feet) so it can reach around to your iPod.

Take your stereo cable and solder the end of it to the board as in the picture above. The left most soldering point is GROUND. The second one is RIGHT CHANNEL and the 3rd is LEFT CHANNEL. Referenced from here: http://en.wikipedia.org/wiki/TRS_connector

Test to see that everything is connected correctly and that you did not create any shorts.

Tape the cable to the back of the tape mechanism so it does not get pulled and take the soldering points with it.

Now, a little trick. If you look at the picture below you will see a small, black micro switch in the center of it. It has 4 legs and it tells the radio that you have inserted a tape in it. When you put the tape in a mechanism of levers will release this switch and will operate the tape loading arms. We need to disable the switch and we do this by removing the spring and then pushing the arm that is holding the spring down.



Tape the spring and the arm to the top of the tape mechanism so they don't move. I left the spring in there in case I ever want to put it back together.

Tape used mode, see picture below...



Put everything back together. Put the tape mechanism back in it's place and the screws that hold it. Route the cable inside the radio so it is not disturbing the top cover.

Back to the car.

Put your finger through the hole in the top of the sunglasses tray and push the climate control unit out. You DO-NOT need to disconnect it.

Route the cable like in the picture. In through the right back side area of the radio location and down through the hole in the sunglasses tray.

Install the radio back. First plug the cables. Turn the key on and turn the radio on. It will ask for the code (I hope you have it) and then you will hear the tape mechanism work loading the nonexistent tape. This is because we have set the micro switch to TAPE IN position. It will only happen once.

Connect an ipod and press the TAPE/CD button. It will show TAPE A and you will hear your iPod. Press the button again and it will operate your CD changer.

Push the radio back in and use the radio key to turn the screws. Put the climate control unit back in.

If you want to have the option to charge the iPod as well you can buy this: http://www.griffintechnology.com/products/autopilot

You plug your AUX input to the AutoPilot and the iPod to the AutoPilot iPod connector. This way you only have one plug to connect your iPod to when you put it in your car and it will charge it and play the music.

Picture of final installation. The iPhone cradle is also made by Griffin.

[Rick L]

Final picture with TAPE selection to access tape line-in for iPod or other MP3 players. And you get to keep CD changer. But maybe you can do similar with orther radio with tape player or even put toggle switch for line-in from CD changer as well...

[repenttokyo]

That's a great tutorial. Unfortunately, I don't have a CD player in my trunk, so I am not sure that any of that applies to me.

[uscharalph]

If you have a C43 you can use a DICE unit. CD43 is better. iPod is better also.

[repenttokyo]

How do I know what model radio I have?

[tim eh?]

That's a great tutorial. Unfortunately, I don't have a CD player in my trunk, so I am not sure that any of that applies to me.

that is the #1 way to go dude - you would be stealing the deck's hardwired 'tape in' and turning into an external aux in.... then you can run anything to it. the only trick is finding the L/R/ground on the circuit board in the radio. i'm sure a radio/tv repair guy would do it for cheap if you don't want to. nice writeup rick!

don't get those FM transmitters they are super lame, you lose sound quality in the FM conversion/reversion.

an aftermarket stereo is pretty easy, even if you can't find an appropriate connector/adapter on ebay the wiring is pretty self-evident. on the head unit you only have hotalways/hotwithignitionon/ground plus the speakers (8 wires) plus a remote power send for the factory amp also. the bummer is unless you do the amp bypass you aren't getting the most out of your new head unit, but it still works alright. the grounds aren't a worry... there is a place to ground them on the amp input... common advice seems to be to tie them together but i still disagree with that. i still would suggest option #1 as fastest, easiest, and cheapest.