Afternoon Gaz,
I’ve not personally had to do this retrofit before but you'll need to collect the parts required:
1. Blaupunkt amplifier
2. 2x speakers
3. VCDS for any specific coding
4. Associated pins and wiring
These parts should be readily available from one of our resident ethical breakers. Place a Wanted add in the Market area as one of them may be willing to remove the whole loom for you instead of just cutting the connectors.
Once you have these parts you’ll need to add the necessary feeds at the head unit mini ISO connectors and take them down to the Blaupunkt amplifier:
Mini ISO connector (20 pin):
1 - rear left signal
2 - rear right signal
3 - signal ground
6 - Plus switched (amplifier)
Pins 1,2 & 3 should be shielded to avoid interference, everything you need will no doubt be in someone’s breaker.
Blaupunkt Amplifier Connector (12 pin):
1 - Speaker (-) rear left
2 - Terminal 30
3 - Terminal 31
4 - Signal ground (from head unit)
5 - Switched live (from the head unit)
6 - Speaker (+) rear right
7 - Speaker (+) rear left
9 - rear left signal (from head unit)
10 - rear right signal (from head unit)
12 - Speaker (-) rear right
From the amplifier you’ll need to take pins 1,6,7&12 to the handed internal B pillar connectors and then from the exterior B pillar connectors through the doors to the speakers themselves.
Written down like this is looks quite straightforward but you’ll have to remove various trim panels. As Ian
@Proghound says above, it might just be easier to get someone to do it for you but that removes the satisfaction of doing it yourself.
Kind regards,
Tom