89 530i Central Locking stays open

[bagpuss]

Been offered this car (UK spec), not seen it yet as its 50 miles away. Fault it that the Central Locking stays open all the time - does not lock. I know its hard to say exactly what the fault could be but on the balance of probabilities, is it 'likely' to be a fairly simple/cheap fix and is there a small 'checklist' that the fault is 'likely' to be ?

Cheers.

[angusbn]

Check the 7.5AMP fuses that control the central locking system.