Hi, I'm about to install my new Alpine CDE-100EUB, and am checking out the wiring to the stock unit.

There's the fat plug with lots of wires, I can probably cope with that.

But there's an additional small plug with a single thin blue wire. What is this?

Does anyone know where I can find the factory wiring diagram for the wires connecting to the stock radio? I've got both the CD version of the manual and can't find it there, and the downloaded version, which I can't get to run.......

Peter.

The blue wire is for a phone system.

The circuit diagram is in the manual, it's just buried nice and deep.

Main -> Chassis Electrical -> Circuit Diagrams -> Audio System

If you can get your hands on one of these, it makes installation much simpler.

http://cgi.ebay.com.au/MITSIBISHI-MAGNA-stereo-WIRING-HARNESS-plug-and-loom_W0QQitemZ360178454648QQcmdZViewItemQQptZAU_Ca r_Parts_Accessories?hash=item53dc4f1078&_trksid=p3286.c0.m14

As mentioned above, the single blue wire in a separate plug on the OEM head-unit is the Phone Mute wire - comes from a connector under the lower console near the underside of the cupholders. In cars with the steering wheel audio remote controls, the wire for remote also comes into that separate plug.

Wiring diagrams for audio system should be easily found as correctly stated above - there are separate diagrams for the 4-spkr audio, and another for the 6-spkr and 8-spkr audio. Under each page of the circuit diagram there is a series of diagrams showing the shape and pin-out of the various electrical loom connectors.

With the "mouth-organ" plug for the Head unit power and audio-out, be aware that there is NO ground/earth wire in the car loom..... Mitsi head-units are grounded through their casing and the metal mounting brackets. If you aftermarket head unit has a ground wire (likely) DO NOT connect it to any wires at all in the car loom-plug for radio - find a nice metal screw/bolt in the dash which attaches to a metal bracket, and put the new radio earth wire there!! Hopefully you will solder on a spade/loop/fork electrical connector on the ground wire and then attach that to a metal bit behind the dash.