B8 GT estate - electric seat controls failed

[Langlineer]

Hi

Newbie; searched but didn’t find anything

B8 GT estate. Drivers seat has electronic controls for recline and lumbar support, but don’t work (they never have since I bought it approved used a year ago - but that’s another story).

Problem solving this myself
- no faults reported on OBD2
- replaced thermal fuse for drivers seat anyway; no difference

Any ideas what to try next?