Rover 25 Central Locking
OK, just fixed mine. Here's what I did. As already said, check the cables where they go through from the car into the boot. The cables go through a rubber tube at the top right by the hinge, hose for wash wipe goes through the left hand one. I found several of the cables damaged and shorting out, which in turn blew something other than the 15a fuse in the engine compartment as the immobiliser still operated and is on the same supply.
Once the cable were repaired, locate the control unit for the central locking. It is behind the fuses on the drivers side, under the dashboard. It is above the accelerator pedal and is held in place by two 10mm plastic nuts. It is a black box about 6" by 4" with a white label on, mine had a large letter D on the label, made by Lucas.
Disconnect and remove the unit - unplug. Warning it is a swine to get to. Take all the obvious safety precautions like disconnecting the battery first (did mine without, but I'm not taking the blame if you short or blow something)
With the unit out, undo the plastic clips holding it together. Open up and remove the circuit board. On mine one of the tracks had blown apart due to switching with a short circuit. Solder the track back together. Reassemble.
My wife's car is now fully working, total job time for everything was about 3 hours, but be warned, it is a pig to get to the unit. I did drop the fuse board down and unplug a few cables to help.
Here is a link to the box you are looking for so you can see what it looks like.
http://www.remotekey.co.uk/cars/rover/rover-25/faq.asp
Hope this helps.
Dave