I did my best to check that I had a high line BeCM before getting this far - though mistakes can happen. The sticker on top of the unit was too worn to read, but I do have a sunroof, a mid-line stereo, and the original seat had some power adjustment. So, fingers crossed I'm OK on the BeCM front, and there's no 'activate' option. That's a step forward.
I'll need to find the wiring diagrams I think. The length of the looms and relatively inaccessible plugs under the seat won't help when trying to test things.
If I removed the seat, and the loom, would I be able to test power from the BeCM socket?
EDIT - stand down, thanks. I'd made a 'numpty level' mistake which I noticed this evening. I now have the driver's seat behaving perfectly and can move on to the rest. I do have the wing mirrors playing silly b*ggers as was mentioned on the first page of this, but I'll sort that.
So, it was in fact 'plug and play' - but the important thing about that is that you actually need to plug everything in....
This plug is part of the seat loom.
I thought it would fit onto the seat, but there was no connector there... so I thought it was maybe for a function on the seats that my car wouldn't have. A closer look today, in better light found this socket (highlighted) hiding down under the fuse box.
I checked really carefully that the two were compatible and as the wires were exactly the right length I plugged it in and.... the seat worked OK. I wasn't looking forward to spending an evening with the electrical manual identifying wires and colours, looms and connectors so that's a result.