radders567

I am half way through gathering the parts myself. What control unit are you referring to?
 
I have the following
Loom - Obtained from Eddie-NL.
Climapanel - Obtained from Woody. 
Heat pads - Bought from SKODA.
 
Part numbers for heating pads   2x 1Z0 963 557N 2x 1Z0 963 556B 2x 1Z0 963 555A   Seat wiring loom   1Z0 971 365DL (Drivers side)
1Z0 971 365DN (Passenger side)
  Climatronic Panel with heated seat control   1K0 959 772 or 1Z0 959 772     Fitting info for wiring loom from Eddie-NL
 
Red Wire = Fusebox constant 12v
 
Brown = Ground
 
wire from (Pin 1) ten pin plug (one with more wires) goes to pin 21 on BCM plug B
wire from (Pin2 ) pin 10 on Climatronic T20
wire from (Pin 7 ) pin 11 on Climatronic T20
 
Hope this helps.

I've not heard many people complaining of the CR turbo playing up due to carbon deposits, I have however heard of the electronic actuator failing.  This may be your case.  As you have access to VCDS maybe you could test it ?

Are there any small round vent plugs on the side of the battery top. In some applications these have a little tube attached to vent any gasses away from the battery.