VDO DAYTON 4200MS INTO A4 B5

[sirmarky]

I connected my dayton sat nav radio into my a4 the other night , i plugged in the two standard black & brown plugs and the 3 mini iso (yellow green blue) blocks into the dayton head unit.
there was a red plug with 3 wires attached to it that had no place to plug in , but it was connected to the original audi head unit.
The dayton will play radio & cd's , through all speakers but doesnt sound very good , my main problem is that the boot cd changer wont power up or even eject , it worked on the original unit.
What is this large red plufgfor ? reading through the forums i see it could be amp wiring ?
but why wont my changer work ? , the blue mini iso is connected , which according to the vdo dayton intructions is the cd changer plug...
do i need to power up the amp from this red plug ?

please help

mark

 

[aragorn]

From memory, the CD changer power or ground comes from that red plug.

Look at the schematic drawing on the top of the old head unit.

 

[sirmarky]

Old head unit has no diagram , its a concert cassete type...
also the rear speakers dont appear to work , reading into this they have an amp ? ho do i power this up ?
I was thinking about putting the old concert unit back in but i have no code , is it possible to get the code through vagcom ? .. vagcom has a section for radio doesnt it ?
or am i stuck with seeing the stealers ?

thanks for any help

mark

 

[sirmarky]

UPDATE:
I had a mess with the wiring , changed the earth wire around on the blue mini iso plug and got the cd changer powered up but the head unit wont recognise it...
i managed to get all the speakers working too with reasonable sound...
but im bugged as i'd like to run the cd changer in the boot , is there a adaptor lead to enable me to connect the changer to the vdo dayton unit ?
the changer is the original factory fit..

mark