Tonight has been a night of testing.
Plugged the battery in, ECU and PAS ECU.
Fired up Forscan and carried out a Key on engine off test. Ended up getting a fault on cooling fan 1.
Double checked the relay socket and found the switching wiring terminal loose. Popped it back in the socket and all is well.
Got the rear fog light wiring as well. That was a combination of getting wiring terminals mixed up + a dodgy fuse board terminal.