Advice on radio wiring

[GlynRS2]

I am planning to fit a Chorus 2 head unit into my RS2.
I have noticed that the pins for the black connector are labelled slightly different to before. So before I cause a meltdown I thought I would ask for some advice. To show you what I mean I have uploaded this picture:

My concerns are:
1) Pin 1 currently connects to the speed sensor output from the instrument panel, whereas it is now labelled BOSE on the Chorus 2 head unit
2) Pin 3 is a connection to the Battery +, whereas on the Chorus 2 it is labelled K-BUS (I think this is the system which enables you to both be able to turn on the radio independantly of the ignition switch and then be turned off by the ignition at the same time - i.e. intelligent switching).
Do you think it will be OK just to plug in the black connector & see if it works, or do I need to do some remedial wiring first?

[s2avant]

I would need to look on ELSA (Workshop computer) to get you the wiring schematics for the chorus II. What car is it from?

I'll try and have a look tomorrow.

Ben

[GlynRS2]

Ben,

Thanks - it is from an A2

[s2avant]

Looking at the schematics for the chorus II it's a good job you didn't just plug it in.:eek2:

The wiring is as follows:
[list=1][*]gala (speed signal) only upto MY01[*]Telephone Muting (Up to MY01) / ATA earth (MY02 on)[*]K diagnosis (Used for diagnostics on the radio)[*]Terminal 86s (S contact) upto MY01[*][*]Switch Illumination (terminal 58s) up to MY01 [*]Battery + (terminal 30)[*]Earth (terminal 31)[/list=1]

Have you got a copy of the pin assignments off the top of the radio?

Ben

[GlynRS2]

The markings on the top of the Chorus 2 radio are:

Pin 1 BOSE
Pin 2 DWA-GND
Pin 3 K-BUS
Pin 4
Pin 5
Pin 6
Pin 7 UB+ (terminal 30)
Pin 8 earth (terminal 31)

So I guess it is a 92MY unit ( which figures with what I thought)
This unit has a seperate plug running vertically next to the usual 3 connectors for connection to telephone & Sat Nav etc
So I am probably best off doing the following:
Not connecting anything to Pin 1.
Connecting Pin 2 to earth.
Not connecting anything to Pin 3
But probably ok to leave Pins 4 - 8 the same
Does that sound ok?

[s2avant]

I would try it with pin 2 disconnected as well. It should only need the other four connected to work.

IIRC earthing pin 2 will mute the speakers.

Ben

[GlynRS2]

Thanks for that Ben - I will give it a go at the weekend.
Leaving pins 1-3 not connected.
I will let you know how it goes

Glyn