Head unit replacement ... HELP ... its not working

[pallaire]

Hello guys,

I have a BWM Z4 2.5i 2003, I bought it used last summer. My BMW headunit was having problems and I wanted to have a real iPod/iPhone connection so I wanted to change my radio.

I have looked at many tutorials, many videos and I am a bit lost. Looks like every Z4 is different!!!


I was successful at :

1. Opening the Central Vent
2. Unplug the original unit
3. Plug my new unit

Result: no sounds ... but unit is working (ie have power)

So I have done more research, I have read that if the car have an amplifier, I may need to go by RCA cables instead of the original connectors ? Do my car have an audio amplifier ?


When I did the connection of the new head unit to the Scosche adpater, I followed to color code of the wires. but when I look at the back of both connectors (cars and apapter) I can see some mismatches !!!


So what would be the main source of my problem ? bad wire mapping or do I need to go through the amp ? photos following



Looking for an AMP:

There is nothing plugged behind the carpet in the trunk:


Is this an amplifier next to my battery ?


If so ... How am I supposed to plug RCA Cables into that unit?




Wire color mapping:


The green circle shows connectors that are connected in the the headunit by the Scosche adapter but those connections goes no where in the car. And the Pink circle are use by the car but not on the Scoche adapter


This is the connection:



So finally ...

If I do indeed have an amplifier ... how do I connect to it ?

If its only an adapter color code problems, where can I find the information on HOW to connect to it ?

Thanks guys.

[philly_Z4]

Not sure if this will help but here's the radio wiring diagram for the 2003 Z4

2003 BMW Z4 Car Stereo Wiring Guide
Car Radio Battery Constant 12v+ Wire: Red/Yellow
Car Radio Accessory Switched 12v+ Wire: Violet/White
Car Radio Ground Wire: Brown
Car Radio Illumination Wire: Gray/Red
Car Stereo Dimmer Wire: N/A
Car Stereo Antenna Trigger Wire: White
Car Stereo Amp Trigger Wire: N/A
Car Stereo Amplifier Location: N/A
Car Audio Front Speakers Size: N/A
Car Audio Front Speakers Location: N/A
Left Front Speaker Positive Wire (+): Yellow/Red
Left Front Speaker Negative Wire (-): Yellow/Brown
Right Front Speaker Positive Wire (+): Blue/Red
Right Front Speaker Negative Wire (-): Blue/Brown
Car Audio Rear Speakers Size: N/A
Car Audio Rear Speakers Location: N/A
Left Rear Speaker Positive Wire (+): Yellow/Violet
Left Rear Speaker Negative Wire (-): Yellow/Gray
Right Rear Speaker Positive Wire (+): Blue/Violet
Right Rear Speaker Negative Wire (-): Blue/Gray

[DataStream18]

Yes that is your amp but factory amps on out age Z's do not have rca hook up points.

[RichardP]

Your problem is that the DSP amp that you have requires a signal from the BMW radio to turn on. This signal is passed over the cars data bus called the iBus, the bottom wire thats circled in magenta is the iBus wire.

To use the DSP amp you will need a BMW radio and you will need the iBus wire connected, without thsoe you will get no sound.

If you are not using the BMW radio then you must replace the BMW amp.