I'm pretty sure I've got the right wires - going by their colour codes and also the fact that connecting the permanent live and ground wires results in sparks and then a blown fuse...
I've taken everything apart in the nav casing looking for any sign of a short, but no joy. To isolate the component causing the issue, I first removed the wiring harness I was using, and connected the wires to the bare pins at the back of the control circuit board with spade connectors. But still the same problem - I connected the ground wire first, and then as soon as I connected the permanent live, the connection sparked for a moment and then the fuse blew. So it's safe to say that the harness isn't causing the issue.
I then disconnected the open/close and tilt buttons, and the motor from the control circuit board so the only component in the circuit was the control circuit board and tried again, but with the same result. Could something be wrong with the board? I removed it from the casing and inspected it, but all the pins seem fine and there's no visible sign of any damage to the board.
I'm really at my wit's end with this, and the number of new 20A fuses I've installed over the last few days is now flirting with the ridiculous... :tsktsk:
To top it off, my stereo isn't working now. When I plug the cable into the back I can hear the changer whirring so there's definitely power going to it - yet it doesn't switch on. I'm guessing maybe the Radio 2 fuse has blown? As I remember, that's in the driver's side footwell, which is a right pig to access...