So I found a second hand PSE pump on eBay, at a very good price, cleaned all the contacts, connected it up and...nothing! Then checked the fuses a d they had blown. Replaced these and now have central locking and interior lighting!
So I guess this central locking pump will not be working again! Looking round for a replacement, but what worries me is the connectors. These look rusty as well and I am concerned about plugging them onto a new unit!