Radio gremlins

[stratos]

Hi the audio 10 radio cass' im my 01 clk stays on with engine off, and doesn't light up.
I found a car telephone lead and black box installed between the cars iso leads and the radio.
I removed this and plugged back in the original leads.
I read somewhere that a switched 12v cable is not used to power up radio with the ignition, but rather it is sensed on some sort of in-car network or bus.
Sounds like a complicated way of doing something simple, so i don't know if thats correct.
Any ideas anyone ?
Happy new year and good motoring.

 

[stratos]

Well I have looked at this a little further, and I am puzzled by what I found.
The ISO connectors on the car especially the socket "A" has very few pins.
Missing crucially are , a switched +12v to switch the radio on with the engine (pin 7), and an illumination +12v which comes on with the car lights to illuminate the radio (pin 6).

Now the audio 10 radio/cass installed in the car needs these 2 connections.
It was just a matter of jumping a wire from pin 4 (+12v) to pin 6.
this allows the radio to be illuminated, albeit all the time it is switched on.
I will have to find an ignition switched circuit to fix the other part.

This however points to the fact the audio 10 in my car is not the factory installed radio, I don't think Mercedes would supply a car with a dark radio.
I did find it surprising to find an 01 car with a cassette deck rather than cd player.
Does anyone know what the standard radio fitment was on an 2001 clk ?
Or anyone have any other explanation ?