I am in the process of installing an aftermarket radio in an E30 and need a wiring diagram specifically for the radio. Bentley doesn't cover the radio (at least I haven't found it in section 14 or 15). There must be an old post out there with a link to a diagram, cripes the car is over 20 years old. thanks...
This particular article applies to the E36, but give it a look...there might be some similarities somewhere along the lines... http://www.pelicanparts.com/bmw/techarticles/E36-Radio/E36-Radio.htm Hope it comes in handy. This website has a lot of good DIY topics.
Gonna try and do this from memory as I unfortunately have not had an E30 in quite some time: 12 volt switched Violet/White or Violet/Gray 12 volt constant Red/White (this is a heavier gauge wire than the rest of the harness Ground Brown (should be about the same gauge as the 12 volt constant Power Antenna/Remote White Illumination Gray/Red For Speakers the Left Speakers should be Yellow/Red for Front, Yellow/Black for Rear positive Right Speakers Blue/Red Front, Blue/Black Rear for Positive All of the Negatives are Brown with another color tracer, I forget what color. If you have the fader in the dash, and a factory amplifier outside of the headunit then it may be in your best interest to run new speaker wires,
OK, here are my suggestions. I have wired many E30s and E28s and found that some of the higher powered modern stereos will overpower the original circuit. The original circuit is wired so that the switched power provides the bulk of the power for the radio amp. The memory power is only there to keep the station memory. Most modern steroes work differently. The switched power is just a low power turn on signal, and the main power for the amp comes in through the always on power (memory power.) The always on power on most modern stereos is a dedicated 10A fuse. The 7.5A circuit that the E30 has is shared with the dome lights, trunk light, check control, cluster, and other stuff. On my M5 I installed Rockford head unit (25W RMS per channel) and when I had the hazards on and the bass hit, it blew the fuse. A similar thing would happen on the E30, except not with the hazards. If you have high powered radio, do yourself a favor and wire the switched power up the way you normally would, but run a big fat wire to the aux fuse box (right next to the main fuse box, made especially for add on accessories) to the always on power. Next caveat is that the stock speaker wiring goes through the fader and has a common ground. Do not common ground the speakers for a modern stereo, it really messes with them if you use the stereo's fader at all. I run new speaker wires to all the speakers.
