Radio wiring - I don't get it...

[TB2]

Hi.

I want to replace the old radio in my BX with a newer one, which has a standard ISO plug. But the old wiring is somehow confusing, and I don't get what the previous owner - or whoever did the wiring - was doing. Here's a picture (click to enlarge)



The easy part were the 2x2 speaker connectors, which were labeled by Citroen. They are 2x brown and 2x green and have those big white connectors at the ends. The blue one is the antenna cable. But I don't really get what all the other cables are supposed to do.
When I removed the old radio, the thick yellow cable (more to the right) and the grey cable weren't connected at all. As you can see, the grey one even has some tape on it - both of them have typical Citroen connectors on them.
The two cables that were connected to the radio were the red cable and the thin yellow cable (on the left, continous as a black cable), both of which have fuses in those plastic tubings.

The place where the red cable was connected is described on the old radio as "+ To car fuse box; Fuse 5A". And where the yellow cable was it tells "Battery + B; Fuse 0.2A".

The red cable is somehow attached to one of the 3 grey cables which run at the back of the radio slot. I don't know where they are heading, or what their purpose is.

The yellow cable runs in the same direction as the <2x2 Speaker, thik-yellow and grey> chunk runs, somewhere up to the steering wheel (which is on the left btw ) I think these cables (without the yellow/black one) were originally put there by Citroen.

I didn't find a simple ground cable at all. Should there be one? Because the old radio didn't function properly, it was always on (even if the volume/power-wheel was turned to "off") but there was no sound at all. But this could be the radio, or besides of that, 2 of the cables on the back of the radio led nowhere...

The simple things I am missing to connect to my new Radio are:

-> always-on +
-> ignition- on +
-> ground

So which one of there cables there do I need? What about the original Citroen cables, or the new red and yellow ones...
Could someone help me clean up this mess?

Thanks!

PS: Oh dear -.- why are there three of them...

[jeremy]

Have a look at P34 of the drivers manual.

BX are wired so that the radio is on all the time - so that the tape doesn't tangle on starting - so its necessary to connect the supply terminal (yellow wire) to both the unswitched supply (memory terminal) and the unit supply.

If your set is modern and has an electronic switch rather than a click type if you wire it this way the battery will probably flatten over a few days as modern electronic sets draw a standby curent. To avoid this it will be necessary to find an alternative supply switched with the ignition for the main set supply and use the existing yellow cable for the memory.

Drivers handbook - here:

http://www.rwbsmith.plus.com/citroen2/D ... rsbook.pdf

[TB2]

I see, thanks!

So, I guess that one of those two additional wires is triggered with the ignition. But which one would it be? I mean the yellow wire with the red connector wasn't used with the old radio I removed, so it must have gotten it's power from one of those two wires...

The red "+ To car fuse box; Fuse 5A" cable or
The yellow "Battery + B; Fuse 0.2A".

I guess "to car fuse box" could mean that it's triggered with the ignition, right?

[jeremy]

Yellow sounds like the original lead - red may be switched - check it with a test lamp or meter or something and see when it functions.

You can get nice plugs and sockets to fit the ones on the radio from Maplins or Halfords. They will need to be fitted to the car wiring.