BMW E30 central locking not working
E30 central locking is not working – what usually causes it?
The fault is often in the central locking control box, which is on the driver's side behind the kick panel, low down under the speaker. The most common cause is a burnt fuse wire or a loose solder joint; resoldering the joint has fixed the fault.
The control box is fine, but the driver's door lock does not work. What should I check?
Check the connector between the door and the body: the pins may be oxidised or broken. The same connector carries the door's other electrics too, so for example a simultaneous fault in the power mirrors points to it. Also check the wires of the door sleeves.
The lock motor does not move or the driver's door does not lock the other doors. What can I do?
The lock motor can seize with rust; removing it, greasing it and using a rust inhibitor has restored movement, but a more lasting solution is a new motor. If the slot in the lock body is worn, the lock mechanism must be replaced. The relay contacts can also be worn or welded shut.